Patent US3921035A successfully refreshed from Google Patents.
US3921035A
Expired / Lapsed
US
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Solid state switching circuit
Assignee: Esquire Inc
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Filing: 1974-07-18
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Granted: 1975-11-18
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Expires: 1994-07-18
Abstract
Abstract A switching circuit employed in one aspect of the invention a high intensity discharge lamp ballast, the switching circuit having high efficiency switching characteristics over a wide range of applied current conditions, temperatures and voltage variations and providing good regulation to the lamp. A Darlington pair operating in conjunction with a current source is used in a preferred embodiment for the switching device, the current supplied by such current source being dependent on the ratio of load resistors rather than on the product of the betas of the transistors. The switching device may also be employed in circuits other than lamp ballasts, such as in circuit breaker applications and in operating light emitting diodes. Furthermore, the heart of the switching device may be packaged in a convenient capsule for diverse applications as selected by the device user.
Inventors
- 👤 Kenneth P Holmes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:26
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/28; H03K17/292; H02; H02M; H02M3/00; H02M3/02; H02M3/04; H02M3/10; H02M3/145; H02M3/155; H02M3/156; H02M3/1563; H03K17/51; H03K17/56; H03K17/60; H03K17/615; H03K17/64; H03K3/00; H03K3/02; H03K3/26; H03K3/28; H03K3/281; H03K3/286; H05; H05B; H05B41/00; H05B41/14; H05B41/36; H05B41/38; H05B41/39; H05B41/392; Y; Y10; Y10S; Y10S315/00; Y10S315/07
Claims Analysis
Total Claims: 130
Claim 1
Independent Claim
175 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition, and inductor means for maintaining current through the lamp connected to said switching circuit, the effective current therethrough being approximately constant independent of the frequency of turn on and turn off of said switching circuit.
Claim 2
Dependent Claim
175 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition, and inductor means for maintaining current through the lamp connected to said switching circuit, the effective current therethrough being approximately constant independent of the frequency of turn on and turn off of said switching circuit.
Claim 3
Dependent Claim
32 words
A regulating ballast circuit as set forth in claim 1, wherein said dc voltage input means includes pairs of rectifying diodes connected to input lines from a three phase ac power source.
Claim 4
Dependent Claim
25 words
A regulating ballast circuit as set forth in claim 1, wherein said high gain means of said switching circuit includes a Darlington pair of transistors.
Claim 5
Dependent Claim
80 words
A regulating ballast circuit as set forth in claim 3, wherein said variable current means includes a transistor, the base of which is connected to the series connection point between a diode and the collector circuit of said Darlington pair, said dc voltage input means being respectively connected through said first and second resistances to said transistor and to said Darlington pair, current flow through said transistor being limited by the current gain established by said first and second resistances.
Claim 6
Dependent Claim
25 words
A regulating ballast circuit as set forth in claim 4, wherein said diode has a forward voltage drop approximating the base-to-emitter drop of said transistor.
Claim 7
Dependent Claim
27 words
A regulating ballast circuit as set forth in claim 5, wherein said diode is shunted by a resistor to provide decreased charge storage time of said diode.
Claim 8
Dependent Claim
56 words
A regulating ballast circuit as set forth in claim 1, wherein said high gain means includes a first transistor having a first leakage current reduction resistor connected from the base to emitter thereof and said variable current means includes a second transistor having a second leakage current reduction resistor connected from the base to emitter thereof.
Claim 9
Dependent Claim
61 words
A regulating ballast circuit as set forth in claim 1, wherein said turn-on means includes a capacitor connected to said dc voltage input means and a threshold semi-conductor device connected to said switching circuit, such that a voltage build up of predetermined amount of said capacitor causes a current pulse through said threshold semi-conductor device to turn on said switching circuit.
Claim 10
Dependent Claim
17 words
A regulating ballast circuit as set forth in claim 8, wherein said semi-conductor device is a diac.
Claim 11
Dependent Claim
19 words
A regulating ballast circuit as set forth in claim 8, wherein said semi-conductor device is a silicon bi-lateral switch.
Claim 12
Dependent Claim
19 words
A regulating ballast circuit as set forth in claim 8, wherein said semi-conductor device is a silicon unilateral switch.
Claim 13
Dependent Claim
18 words
A regulating ballast circuit as set forth in claim 8, wherein said semi-conductor device is a 4-layer diode.
Claim 14
Dependent Claim
19 words
A regulating ballast circuit as set forth in claim 8, wherein said semi-conductor device includes a programmable unijunction transistor.
Claim 15
Dependent Claim
19 words
A regulating ballast circuit as set forth in claim 8, wherein said semi-conductor device includes a silicon controlled rectifier.
Claim 16
Dependent Claim
23 words
A regulating ballast circuit as set forth in claim 8, wherein said semi-conductor device includes a programmable unijunction transistor and a Zener diode.
Claim 17
Dependent Claim
23 words
A regulating ballast circuit as set forth in claim 8, wherein said semi-conductor device includes a silicon controlled rectifier and a Zener diode.
Claim 18
Dependent Claim
74 words
A regulating ballast circuit as set forth in claim 1, wherein said turn-off means includes a resistance means connected to supply operating current to said inductor and a charging capacitor and a delay circuit sensing the operating current from said switching circuit, and a semi-conductor device such that an operating current of a predetermined amplitude causes said semi-conductor device to conduct, the charge on said capacitor generates a turn-off pulse to said switching circuit.
Claim 19
Dependent Claim
19 words
A regulating ballast circuit as set forth in claim 17, wherein said semi-conductor device is a silicon bi-lateral switch.
Claim 20
Dependent Claim
19 words
A regulating ballast circuit as set forth in claim 17, wherein said semi-conductor device is a silicon unilateral switch.
Claim 21
Dependent Claim
18 words
A regulating ballast circuit as set forth in claim 17, wherein said semi-conductor device is a 4-layer diode.
Claim 22
Dependent Claim
28 words
A regulating ballast circuit as set forth in claim 17, wherein said semi-conductor device includes a gated semi-conductor, the operating current of predetermined amplitude actuating the gate thereof.
Claim 23
Dependent Claim
19 words
A regulating ballast circuit as set forth in claim 17, wherein said semi-conductor device includes a programmable unijunction transistor.
Claim 24
Dependent Claim
19 words
A regulating ballast circuit as set forth in claim 17, wherein said semi-conductor device includes a silicon controlled rectifier.
Claim 25
Dependent Claim
23 words
A regulating ballast circuit as set forth in claim 17, wherein said semi-conductor device includes a programmable unijunction transistor and a Zener diode.
Claim 26
Dependent Claim
23 words
A regulating ballast circuit as set forth in claim 17, wherein said semi-conductor device includes a silicon controlled rectifier and a Zener diode.
Claim 27
Dependent Claim
63 words
A regulating ballast circuit as set forth in claim 1, wherein said turn-off means is preset for turn-off at a preselected maximum operating current level and the turn-on means is preset for operation for a nominal output from said voltage means and said lamp such that the ratio of on-time to off-time determines duty cycle regulation of constant effective current through said lamp.
Claim 28
Dependent Claim
51 words
A regulating ballast circuit as set forth in claim 1, wherein said switching circuit, turn-on means and turn-off means comprise a two-terminal network, said input means connected to said first and second load resistances through a first terminal and said inductor being connected to said turn-off means through a second terminal.
Claim 29
Dependent Claim
82 words
A switching circuit for connection to a dc source, comprising: means exhibiting high gain over a wide range of applied operating currents, a first load resistance connected to said high gain means, and variable current means regeneratively connected to said high gain means having a second load resistance, and including compensating means for eliminating load current as a factor in determining turn-off current gain, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit.
Claim 30
Dependent Claim
82 words
A switching circuit for connection to a dc source, comprising: means exhibiting high gain over a wide range of applied operating currents, a first load resistance connected to said high gain means, and variable current means regeneratively connected to said high gain means having a second load resistance, and including compensating means for eliminating load current as a factor in determining turn-off current gain, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit.
Claim 31
Dependent Claim
55 words
A switching circuit as set forth in claim 28, wherein said high gain means includes a first transistor having a first leakage current reduction resistor connected from the base to emitter thereof and said variable current means includes a second transistor having a second leakage current reduction resistor connected from the base to emitter thereof.
Claim 32
Dependent Claim
106 words
High speed switching means for connection to a dc source, comprising a switching circuit, including means exhibiting high gain over a wide range of applied operating currents, a first load resistance connected to said high gain means, and variable current means regeneratively connected to said high gain means having a second load resistance, the ratio of said first and second lOad resistances determining the turn-off current gain of said switching circuit, and turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from the dc source when said switching circuit is in the off condition.
Claim 33
Dependent Claim
106 words
High speed switching means for connection to a dc source, comprising a switching circuit, including means exhibiting high gain over a wide range of applied operating currents, a first load resistance connected to said high gain means, and variable current means regeneratively connected to said high gain means having a second load resistance, the ratio of said first and second lOad resistances determining the turn-off current gain of said switching circuit, and turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from the dc source when said switching circuit is in the off condition.
Claim 34
Dependent Claim
106 words
High speed switching means for connection to a dc source, comprising a switching circuit, including means exhibiting high gain over a wide range of applied operating currents, a first load resistance connected to said high gain means, and variable current means regeneratively connected to said high gain means having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, and turn-off mans connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition.
Claim 35
Dependent Claim
106 words
High speed switching means for connection to a dc source, comprising a switching circuit, including means exhibiting high gain over a wide range of applied operating currents, a first load resistance connected to said high gain means, and variable current means regeneratively connected to said high gain means having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, and turn-off mans connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition.
Claim 36
Dependent Claim
140 words
High speed switching means for connection to a dc source, comprising a switching circuit, including means exhibiting high gain over a wide range of applied operating currents, a first load resistance connected to said high gain means, and variable current means regeneratively connected to said high gain means having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from the dc source when said switching circuit is in the off condition, and turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition.
Claim 37
Dependent Claim
140 words
High speed switching means for connection to a dc source, comprising a switching circuit, including means exhibiting high gain over a wide range of applied operating currents, a first load resistance connected to said high gain means, and variable current means regeneratively connected to said high gain means having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from the dc source when said switching circuit is in the off condition, and turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition.
Claim 38
Dependent Claim
25 words
High speed switching means as set forth in claim 32, wherein said high gain means of said switching circuit includes a Darlington pair of transistors.
Claim 39
Dependent Claim
78 words
High speed switching means as set forth in claim 33, wherein said variable current means includes a transistor, the base of which is connected to the series connection point between a diode and the collector circuit of said Darlington pair, said dc source being respectively connected through said first and second resistances to said transistor and to said Darlington pair, current flow through said transistor being limited by the current gain established by said first and second resistances.
Claim 40
Dependent Claim
25 words
High speed switching means as set forth in claim 34, wherein said diode has a forward voltage drop approximating the base-to-emitter drop of said transistor.
Claim 41
Dependent Claim
27 words
High speed switching means as set forth in claim 35, wherein said diode is shunted by a resistor to provide decreased charged storage time of said diode.
Claim 42
Dependent Claim
56 words
High speed switching means as set forth in claim 32, wherein said high gain means includes a first transistor having a first leakage current reduction resistor connected from the base to emitter thereof and said variable current means includes a second transistor having a second leakage current reduction resistor connected from the base to emitter therof.
Claim 43
Dependent Claim
59 words
High speed switching means as set forth in claim 32, wherein said turn-on means includes a capacitor connected to the dc source and a threshold semi-conductor device connected to said switching circuit, such that a voltage build up of predetermined amount on said capacitor causes a current pulse through said threshold semi-conductor device to turn on said switching circuit.
Claim 44
Dependent Claim
17 words
High speed switching means as set forth in claim 38, wherein said semi-conductor device is a diac.
Claim 45
Dependent Claim
19 words
High speed switching means as set foth in claim 38, wherein said semi-conductor device is a silicon bi-lateral switch.
Claim 46
Dependent Claim
18 words
High speed switching means as set forth in claim 38, wherein said semi-conductor device is a 4-layer diode.
Claim 47
Dependent Claim
19 words
HIgh speed switching means as set forth in claim 38, wherein said semi-conductor device is a silicon unilateral switch.
Claim 48
Dependent Claim
19 words
High speed switching means as set forth in claim 38, wherein said semi-conductor device includes a programmable unijunction transistor.
Claim 49
Dependent Claim
19 words
High speed switching means as set forth in claim 38, wherein said semi-conductor device includes a silicon controlled rectifier.
Claim 50
Dependent Claim
72 words
High speed switching means as set forth in claim 32, wherein said turn-off means includes a resistance means connected to supply operating current to the output thereof and a charging capacitor and a delay circuit sensing the operating current from said switching circuit, and a gated semi-conductor device, such that when the gate causes said semi-conductor device to conduct, the charge on said capacitor generates a turn-off pulse to said switching circuit.
Claim 51
Dependent Claim
20 words
High speed switching means as set forth in claim 45, wherein said gated semi-conductor device includes a programmable unijunction transistor.
Claim 52
Dependent Claim
20 words
A regulating ballast circuit as set forth in claim 45, wherein said gated semi-conductor device includes a silicon controlled rectifier.
Claim 53
Dependent Claim
59 words
High speed switching means as set forth in claim 32, wherein said turn-off means includes a resistance means to supply operating current to the output and a capacitor chargeably connected to said resistance means, and semi-conductor means, a voltage build-up predetermined amount on said capacitor causing said semi-conductor means to conduct, generating a turn-off pulse to said switching circuit.
Claim 54
Dependent Claim
19 words
High speed switching means as set forth in claim 48, wherein said semi-conductor means includes a silicon bi-lateral switch.
Claim 55
Dependent Claim
18 words
High speed switching means as set forth in claim 48, wherein said semi-conductor means includes a 4-layer diode.
Claim 56
Dependent Claim
19 words
High speed switching means as set forth in claim 48, wherein said semi-conductor means includes a silicon unilateral switch.
Claim 57
Dependent Claim
19 words
High speed switching means as set forth in claim 32, wherein said turn-on means includes constant current source means.
Claim 58
Dependent Claim
21 words
High speed switching means as set forth in claim 52, wherein said constant current source means includes a field effect transistor.
Claim 59
Dependent Claim
24 words
High speed switching means as set forth in claim 52, wherein said constant current source means includes an npn transistor and a Zener diode.
Claim 60
Dependent Claim
24 words
High speed switching means as set forth in claim 52, wherein said constant current source means includes a pnp transistor and a Zener diode.
Claim 61
Dependent Claim
26 words
High speed switching means as set forth in claim 32, wherein said turn-on means includes a diode for reverse biasing said high gain means during turn-off.
Claim 62
Dependent Claim
27 words
High speed switching means as set forth in claim 32, wherein said turn-on means includes inductor means for reverse biasing said high gain means during turn off.
Claim 63
Dependent Claim
160 words
An encapsulated high-speed switching circuit, comprising: first transistor means exhibiting high gain over a wide range of applied operating currents, second transistor means, complementary to said first transistor means, connected at a first common connection to said first transistor means as a variable current source and having a second terminal suitable for connecting to a second load resistor, the ratio of said first and second load resistors determining the turn-off current gain of said switching circuit, a diode connected to the base of said second transistor means and having a first terminal suitable for connecting to a first load resistance, said diode having a forward voltage drop approximating the base-to-emitter drop of said second transistor means, a second common connection between said first and second transistor means connected to a third terminal, said first transistor means connected to a fourth terminal, said third and fourth terminals providing connections for applying turn-on and turn-off signals to said high speed switching circuit.
Claim 64
Dependent Claim
160 words
An encapsulated high-speed switching circuit, comprising: first transistor means exhibiting high gain over a wide range of applied operating currents, second transistor means, complementary to said first transistor means, connected at a first common connection to said first transistor means as a variable current source and having a second terminal suitable for connecting to a second load resistor, the ratio of said first and second load resistors determining the turn-off current gain of said switching circuit, a diode connected to the base of said second transistor means and having a first terminal suitable for connecting to a first load resistance, said diode having a forward voltage drop approximating the base-to-emitter drop of said second transistor means, a second common connection between said first and second transistor means connected to a third terminal, said first transistor means connected to a fourth terminal, said third and fourth terminals providing connections for applying turn-on and turn-off signals to said high speed switching circuit.
Claim 65
Dependent Claim
65 words
An encapsulated high speed switching circuit as set fortH in claim 58, wherein the values of said first and second resistors are zero, the voltage across said diode and across the base-emitter junction of said second transistor being equal, so that the ratio of the currents through said diode and into the emitter of said second transistor determines the turn-off current gain of the circuit.
Claim 66
Dependent Claim
24 words
The encapsulated high speed switching circuit as set forth in claim 58, wherein said high gain transistor means includes a Darlington pair of transistors.
Claim 67
Dependent Claim
30 words
The encapsulated high speed switching circuit as set forth in claim 58, wherein said first transistor means includes an npn transistor and said second transistor means includes a pnp transistor.
Claim 68
Dependent Claim
30 words
The encapsulated high speed switching circuit as set forth in claim 58, wherein said diode is shunted by a first resistor to provide decreased charged storage time of said diode.
Claim 69
Dependent Claim
54 words
The encapsulated high speed switching circuit as set forth in claim 62, wherein said first transistor means includes a first leakage current reduction resistor connected from the base-to-emitter of a transistor included therein and said second transistor means includes a second leakage current reduction resistor connected from the base-to-emitter of a transistor included therein.
Claim 70
Dependent Claim
85 words
An encapsulated high speed switching circuit as set forth in claim 58, wherein said first and second resistors are connected together and including a third terminal connected to the junction therebetween, and wherein the values of said first and second resistors are zero, the voltage across said diode and across the base-emitter junction of said second transistor being equal, so that the ratio of the currents through said diode and into the emitter of said second transistor determines the turn-off current gain of the circuit.
Claim 71
Dependent Claim
153 words
An encapsulated high speed switching circuit, comprising: first transistor means exhibiting high gain over a wide range of applied operating currents, second transistor means, complementary to said first transistor means, connected at a first common connection to said first transistor means as a variable current source, a diode connected to the base of said second transistor means, a first load resistance connected to said diode, a second load resistor connected to said second transistor means, the ratio of said first and second load resistors determining the turn-off current gain of said switching circuit, said diode having a forward voltage drop approximating the base-to-emitter drop of said second transistor means, a second common connection between said first and second transistor means connected to a first terminal, said first transistor means connected to a second terminal, said first and second terminal providing connections for applying turn-on and turn-off signals to said high speed switching circuit.
Claim 72
Dependent Claim
153 words
An encapsulated high speed switching circuit, comprising: first transistor means exhibiting high gain over a wide range of applied operating currents, second transistor means, complementary to said first transistor means, connected at a first common connection to said first transistor means as a variable current source, a diode connected to the base of said second transistor means, a first load resistance connected to said diode, a second load resistor connected to said second transistor means, the ratio of said first and second load resistors determining the turn-off current gain of said switching circuit, said diode having a forward voltage drop approximating the base-to-emitter drop of said second transistor means, a second common connection between said first and second transistor means connected to a first terminal, said first transistor means connected to a second terminal, said first and second terminal providing connections for applying turn-on and turn-off signals to said high speed switching circuit.
Claim 73
Dependent Claim
185 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit means for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit means is in the off condition, turn-off means connected to said switching circuit means for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit means is in the turned on condition, and high frequency switching means for applying ac current to the lamp, including inductor means connected to said switching circuit means, and relay switching means for providing current through said lamp in a first direction and then in the opposite direction.
Claim 74
Dependent Claim
185 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit means for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit means is in the off condition, turn-off means connected to said switching circuit means for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit means is in the turned on condition, and high frequency switching means for applying ac current to the lamp, including inductor means connected to said switching circuit means, and relay switching means for providing current through said lamp in a first direction and then in the opposite direction.
Claim 75
Dependent Claim
37 words
A regulating ballast as set forth in claim 66, wherein said relay switching means connects said inductor in series with said lamp first one side of said lamp and then on the other side of said lamp.
Claim 76
Dependent Claim
32 words
A regulating ballast as set forth in claim 67, and including a flyback diode to provide a conductive path for current through said inductor when said switching circuit means is turned off.
Claim 77
Dependent Claim
193 words
A regulating ballast circuit for a high intensity discharge lamp, comprising inductor meanas for maintaining operating current through the lamp, a flyback diode connected across the lamp and said inductor means, a terminal for connecting to a standard dc voltage source for applying dc current through the combination of the lamp and said inductor means, switching circuit means connected in the return path of the series combination of the lamp and said inductor means, including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said standard dc voltage source when said switching circuit is in the off condition, and turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition.
Claim 78
Dependent Claim
193 words
A regulating ballast circuit for a high intensity discharge lamp, comprising inductor meanas for maintaining operating current through the lamp, a flyback diode connected across the lamp and said inductor means, a terminal for connecting to a standard dc voltage source for applying dc current through the combination of the lamp and said inductor means, switching circuit means connected in the return path of the series combination of the lamp and said inductor means, including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said standard dc voltage source when said switching circuit is in the off condition, and turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition.
Claim 79
Dependent Claim
21 words
A regulating ballast circuit as set forth in claim 69, wherein said external means is a dc variable control voltage source.
Claim 80
Dependent Claim
72 words
A regulating ballast circuit as set forth in claim 69, wherein said turn-off means includes a resistance means and a charging capacitor connected to said external means for sensing the operating current from said switching circuit, and a gated semi-conductor device connected to said resistance means and said capacitor such that when the gate causes semi-conductor device to conduct, the charge on said capacitor generates a turnoff pulse to said switching circuit.
Claim 81
Dependent Claim
43 words
A regulating ballast circuit as set forth in claim 71, wherein said turn-off means includes a time constant delay means for providing noise immunity and for preventing a false turn-off input because of the presence of an extraneous voltage with respect to time.
Claim 82
Dependent Claim
199 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, turn-off mans connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition, inductor means for maintaining current through the lamp connected to said switching circuit, the effective current therethrough being approximately constant independent of the frequency of turn on and turn off of said switching circuit, and double-pole, double-throw relay means connecting said inductor means to the lamp so that the terminals of the lamp may have polarity reversals applied thereto.
Claim 83
Dependent Claim
199 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, turn-off mans connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition, inductor means for maintaining current through the lamp connected to said switching circuit, the effective current therethrough being approximately constant independent of the frequency of turn on and turn off of said switching circuit, and double-pole, double-throw relay means connecting said inductor means to the lamp so that the terminals of the lamp may have polarity reversals applied thereto.
Claim 84
Dependent Claim
26 words
A regulating bAllast circuit as set forth in claim 73, wherein said relay means includes ac drive means for causing polarity reversals at a periodic rate.
Claim 85
Dependent Claim
72 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, LC circuit means connected to the lamp, polarity reversing electronic switching means connected to said LC circuit means and to said lamp for supplying alternately directed current paths therefrom through the lamp, and ac drive means connected to said polarity reversing means for causing ac current to the lamp via periodic switching of said LC circuit means.
Claim 86
Dependent Claim
72 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, LC circuit means connected to the lamp, polarity reversing electronic switching means connected to said LC circuit means and to said lamp for supplying alternately directed current paths therefrom through the lamp, and ac drive means connected to said polarity reversing means for causing ac current to the lamp via periodic switching of said LC circuit means.
Claim 87
Dependent Claim
151 words
A regulating ballast as set forth in claim 75, wherein said polarity reversing electronic switching means comprises synchronous complementary switches, each of said complementary switches including electronic closure means exhibiting high gain over a wide range of operating currents and having a first load resistance, variable current means regeneratively connected to said electronic closure means having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said electronic closure means for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said electronic closure is in the off condition, and turn-off means connected to said electronic closure means for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said electronic closure means is in the turned on condition.
Claim 88
Dependent Claim
189 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit means for generating a turn-on input thereto depending in time on the level of output from said dc voltage means when said switching circuit means is in the off condition, turn-off means connected to said switching circuit means for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit means is in the on condition, an autotransformer connected to said switching circuit means for stepping up the voltage therefrom, and inductor means for maintaining current through the lamp connected to said autotransformer, the effective current therethrough being approximately constant independent of the frequency of turn-on and turn-off of said switching circuit.
Claim 89
Dependent Claim
189 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit means for generating a turn-on input thereto depending in time on the level of output from said dc voltage means when said switching circuit means is in the off condition, turn-off means connected to said switching circuit means for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit means is in the on condition, an autotransformer connected to said switching circuit means for stepping up the voltage therefrom, and inductor means for maintaining current through the lamp connected to said autotransformer, the effective current therethrough being approximately constant independent of the frequency of turn-on and turn-off of said switching circuit.
Claim 90
Dependent Claim
22 words
A regulating ballast circuit as set forth in claim 77, and including a flyback diode connected across the lamp and said inductor.
Claim 91
Dependent Claim
214 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is In the turned on condition, a transformer connected to a first terminal of the lamp, and a capacitor connected between a common connection of the primary and secondary of said transformer and the second terminal of the lamp, the starting voltage on said lamp being the stepped up full voltage supplied to said transformer, a full charge on said capacitor converting the primary and secondary of said transformer into a series choke for providing operating voltage across said lamp.
Claim 92
Dependent Claim
214 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is In the turned on condition, a transformer connected to a first terminal of the lamp, and a capacitor connected between a common connection of the primary and secondary of said transformer and the second terminal of the lamp, the starting voltage on said lamp being the stepped up full voltage supplied to said transformer, a full charge on said capacitor converting the primary and secondary of said transformer into a series choke for providing operating voltage across said lamp.
Claim 93
Dependent Claim
209 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition, inductor means for maintaining current through the lamp connected to said switching circuit, the effective current therethrough being approximately constant independent of frequency of turn on and turn off of said switching circuit, and said switching circuit means including a high power transistor and a low power drive circuit, such that a low voltage of predetermined value controls the operation of said high power transistor in said switching means.
Claim 94
Dependent Claim
209 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition, inductor means for maintaining current through the lamp connected to said switching circuit, the effective current therethrough being approximately constant independent of frequency of turn on and turn off of said switching circuit, and said switching circuit means including a high power transistor and a low power drive circuit, such that a low voltage of predetermined value controls the operation of said high power transistor in said switching means.
Claim 95
Dependent Claim
29 words
A regulating ballast as set forth in claim 80, wherein said low power drive circuit includes diode means for changing said variable current means into substantially constant current means.
Claim 96
Dependent Claim
233 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition, inductor means for maintaining current through the lamp connected to said switching circuit, the effective current therethrough being approximately constant independent of frequency of turn on and turn off of said switching circuit, and said turn-off means including a resistance means connected to supply operating current to said inductor means and a charging capacitor and Zener diode operative as low power sensing means for sensing the operating current from said switching circuit such that the exceeding of the reverse breakdown voltage of said Zener diode generates a turn-off pulse to said switching circuit.
Claim 97
Dependent Claim
233 words
A regulating ballast circuit for a high intensity discharge lamp, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition, inductor means for maintaining current through the lamp connected to said switching circuit, the effective current therethrough being approximately constant independent of frequency of turn on and turn off of said switching circuit, and said turn-off means including a resistance means connected to supply operating current to said inductor means and a charging capacitor and Zener diode operative as low power sensing means for sensing the operating current from said switching circuit such that the exceeding of the reverse breakdown voltage of said Zener diode generates a turn-off pulse to said switching circuit.
Claim 98
Dependent Claim
110 words
A high speed electronic circuit breaker, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, tHe ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition, and manual turn-on means connected to said switching circuit.
Claim 99
Dependent Claim
110 words
A high speed electronic circuit breaker, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, tHe ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition, and manual turn-on means connected to said switching circuit.
Claim 100
Dependent Claim
137 words
A high speed electronic circuit breaker, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, and turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition.
Claim 101
Dependent Claim
137 words
A high speed electronic circuit breaker, comprising dc voltage input means, switching circuit means connected to said input means including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, and turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition.
Claim 102
Dependent Claim
40 words
A circuit breaker as set forth in claim 84, wherein said turn-off means is preset for turn-off at a preselected maximum operating current level and the turn-on means is preset for operation for a nominal output from said voltage means.
Claim 103
Dependent Claim
58 words
A circuit breaker as set forth in claim 84, wherein said switching circuit, turn-on means and turn-off means comprise a two-terminal network, said first and second load resistances connected to a first terminal and said turn-off means connected to a second terminal, said input means and a load being connected in series with said first and second terminals.
Claim 104
Dependent Claim
56 words
A regulating ballast circuit as set forth in claim 84, wherein said high gain means includes a first transistor having a first leakage current reduction resistor connected from the base to emitter thereof and said variable current means includes a second transistor having a second leakage current reduction resistor connected from the base to emitter thereof.
Claim 105
Dependent Claim
24 words
A circuit breaker as set forth in claim 84, wherein said high gain means of said switching circuit includes a Darlington pair of transistors.
Claim 106
Dependent Claim
79 words
A circuit breaker as set forth in claim 88, wherein said variable current means includes a transistor, the base of which is connected to the series connection point between a diode the the collector circuit of said Darlington pair, said dc voltage input means being respectively connected through said first and second resistances to said transistor and to said Darlington pair, current flow through said transistor being limited by the current gain established by said first and second resistances.
Claim 107
Dependent Claim
24 words
A circuit breaker as set forth in claim 89, wherein said diode has a forward voltage drop approximating the base-to-emitter drop of said transistor.
Claim 108
Dependent Claim
26 words
A circuit breaker as set forth in claim 90, wherein said diode is shunted by a resistor to provide decreased charge storage time of said diode.
Claim 109
Dependent Claim
57 words
A circuit breaker as set forth in claim 84, wherein said turn-on means includes a capacitor connected to said dc voltage input means and a threshold semi-conductor device connected to said switching circuit, such that a predetermined voltage build up on said capacitor causes a current pulse through said semi-conductor device to turn on said switching circuit.
Claim 110
Dependent Claim
16 words
A circuit breaker as set forth in claim 92, wherein said semi-conductor device is a diac.
Claim 111
Dependent Claim
72 words
A circuit breaker as set forth in claim 84, wherein said turn-off means includes a resistance means operably connected to supply operating current to an external load and a charging capacitor and a delay circuit sensing the operating current from said switching circuit, and a gated semi-cOnductor device such that when the gate causes said semi-conductor device to conduct, the charge on said capacitor generates a turn-off pulse to said switching circuit.
Claim 112
Dependent Claim
19 words
A circuit breaker as set forth in claim 94, wherein said gated semi-conductor device includes a programmable unijunction transistor.
Claim 113
Dependent Claim
56 words
A circuit breaker as set forth in claim 94, wherein said turn-off means includes a resistor operating as a current sensing device, and an operational amplifier with its differential inputs connected across said resistor and its output connected to the gate of said gated semi-conductor device, an excess voltage drop across said resistor causing turn-off operation.
Claim 114
Dependent Claim
23 words
A circuit breaker as set forth in claim 96, and including an additional floating dc supply for providing additional voltage for turn-off operation.
Claim 115
Dependent Claim
48 words
A circuit breaker as set forth in claim 94, wherein said turn-off means includes a sensor connected to monitor an external signal, and trigger means operated by said sensor and connected to the gate of said gated semi-conductor device, the presence of an external signal causing turn-off operation.
Claim 116
Dependent Claim
25 words
A circuit breaker as set forth in claim 98, and including a floating dc supply for providing a dc voltage for aiding the turn-off operation.
Claim 117
Dependent Claim
20 words
A circuit breaker as set forth in claim 98, and including isolating means between said sensor and said trigger means.
Claim 118
Dependent Claim
31 words
A circuit breaker as set forth in claim 84, wherein said dc voltage input means is a multiple phase ac input means reduced to a common dc voltage through diode connections.
Claim 119
Dependent Claim
166 words
A high speed circuit breaker for an ac circuit including an ac source and a load, comprising bridge means connected to the ac circuit and having ac and dc terminals, the ac source and load connected to said ac terminals, switching circuit means connected to said dc terminals including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, and turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition.
Claim 120
Dependent Claim
166 words
A high speed circuit breaker for an ac circuit including an ac source and a load, comprising bridge means connected to the ac circuit and having ac and dc terminals, the ac source and load connected to said ac terminals, switching circuit means connected to said dc terminals including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-on means connected to said switching circuit for generating a turn-on input thereto dependent in time on the level of output from said dc voltage means when said switching circuit is in the off condition, and turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition.
Claim 121
Dependent Claim
139 words
A high speed circuit breaker for an ac circuit including an ac source and a load, comprising bridge means connected to the ac circuit and having ac and dc terminals, the ac source and load connected to said ac terminals, switching circuit means connected to said dc terminals including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition, and manual turn-on means connected to said switching circuit.
Claim 122
Dependent Claim
139 words
A high speed circuit breaker for an ac circuit including an ac source and a load, comprising bridge means connected to the ac circuit and having ac and dc terminals, the ac source and load connected to said ac terminals, switching circuit means connected to said dc terminals including means exhibiting high gain over a wide range of operating currents and having a first load resistance, and variable current means regeneratively connected thereto having a second load resistance, the ratio of said first and second load resistances determining the turn-off current gain of said switching circuit, turn-off means connected to said switching circuit for generating a turn-off input thereto dependent in time on the instantaneous level of the operating current when said switching circuit is in the turned on condition, and manual turn-on means connected to said switching circuit.
Claim 123
Dependent Claim
145 words
A bi-stable switching circuit for operating a light emitting diode, comprising high current means exhibiting high gain over a wide range of operating currents, a light emitting diode connected as a load to said high current means and to an external bias voltage, a constant current means regeneratively connected to said high current means having a load resistance connected to said external Bias voltage, the ratio of the current through said light emitting diode and said load resistance determining the turn-off gain of the switching circuit, and said constant current means including a Zener diode connected to said high gain means, such that an external pulse applied thereto greater than the turn-on voltage of said high current means causing sustained conduction of said high current means, said Zener diode and said light emitting diode until the application of an opposite polarity external pulse causes nonconduction.
Claim 124
Dependent Claim
145 words
A bi-stable switching circuit for operating a light emitting diode, comprising high current means exhibiting high gain over a wide range of operating currents, a light emitting diode connected as a load to said high current means and to an external bias voltage, a constant current means regeneratively connected to said high current means having a load resistance connected to said external Bias voltage, the ratio of the current through said light emitting diode and said load resistance determining the turn-off gain of the switching circuit, and said constant current means including a Zener diode connected to said high gain means, such that an external pulse applied thereto greater than the turn-on voltage of said high current means causing sustained conduction of said high current means, said Zener diode and said light emitting diode until the application of an opposite polarity external pulse causes nonconduction.
Claim 125
Dependent Claim
79 words
A switching circuit as described in claim 104, wherein said high current means includes an npn transistor and said constant current means includes a pnp transistor, said npn transistor having its base connected to the collector of said pnp transistor and the cathode of said Zener diode, the collector of said npn transistor being connected to the base of said pnp transistor and said light emitting diode, said external pulse being applied to the base of said npn transistor.
Claim 126
Dependent Claim
30 words
A switching circuit as described in claim 105, and including interface means connected to the cathode of said Zener diode to convert digital logic square wave pulses to spike pulses.
Claim 127
Dependent Claim
133 words
A bi-stable switching circuit for operating a light emitting diode, comprising high current means exhibiting high gain over a wide range of operating currents, a constant current means regeneratively connected to said high current means having a load resistance connected to an external bias voltage, a Zener diode connected to said constant current means and to said external bias voltage, and a light emitting diode connected to said high current means, the ratio of current through said light emitting diode and said load resistance determining the turn-off gain of the switching circuit, an external pulse applied to said constant current means greater than the turn-on voltage thereof causing sustained conduction of said constant current means, said light emitting diode and said Zener diode until the application of an opposite polarity pulse causes non-conduction.
Claim 128
Dependent Claim
133 words
A bi-stable switching circuit for operating a light emitting diode, comprising high current means exhibiting high gain over a wide range of operating currents, a constant current means regeneratively connected to said high current means having a load resistance connected to an external bias voltage, a Zener diode connected to said constant current means and to said external bias voltage, and a light emitting diode connected to said high current means, the ratio of current through said light emitting diode and said load resistance determining the turn-off gain of the switching circuit, an external pulse applied to said constant current means greater than the turn-on voltage thereof causing sustained conduction of said constant current means, said light emitting diode and said Zener diode until the application of an opposite polarity pulse causes non-conduction.
Claim 129
Dependent Claim
82 words
A switching circuit as described in claim 107, wherein said high current means includes a pnp transistor and said constant current means includes a npn transistor, said pnp transistor having its base connected to the collector of said npn transistor and the anode of said Zener diode, the collector of said npn transistor being connected to the base of said npn transistor and the anode of said light emitting diode, said external pulses being applied to the base of said npn transistor.
Claim 130
Dependent Claim
32 words
A switching circuit as described in claim 108, and including an interface means connected to the anode of said light emitting diode to convert digital logic square wave pulses to spike pulses.
References Cited (Backward Citations)
US3626277A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |