US4024457A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hard-firing zero-crossing trigger control circuit
Assignee: Individual
•
Filing: 1975-11-04
•
Granted: 1977-05-17
•
Expires: 1995-11-04
Abstract
Abstract Presented is an electronic circuit composed of various cooperating semiconductor-type devices controlling the degree and timing of triggering of a power switching device to effect controlled electrical conduction through the device. The circuit achieves a "zero-voltage-switch" (ZVS) function where the triggering of the power switching device can occur only during an interval when the main power terminal voltage is less than a predetermined value. The circuit comprises a high-voltage current limiting resistor comprised of a depletion MOSFET or JFET device used as a current limited source to drive other transistor amplifiers and switching circuits, the means of diverting this limited current through application of an external control signal separate from the power terminals, and a means of providing a limited source voltage to the external control means for use if required.
Inventors
- 👤 Grant C. Riddle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:39
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/13; H03K17/136; H02; H02M; H02M5/00; H02M5/02; H02M5/04; H02M5/22; H02M5/25; H02M5/257; H02M5/2573
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
326 words
A control circuit for effecting an instantaneous voltage and current drive to an electrical power switching device to cause said power switching device to suddenly turn ON and latch in a conductive state, said control circuit comprising: a. a pair of external terminal busses of opposite polarity, one positive and one negative; b. an internal controlled power bus of polarity positive relative to said negative terminal bus; c. a current-limited voltage source connected at one end to said positive one of said pair of terminal busses; d. a voltage-limited voltage source connected at one end to said positive one of said pair of terminal busses and at the other end connected to said internal controlled power bus; e. a low-voltage switching control circuit connected between said internal controlled power bus and the negative polarity bus of said pair of terminal busses; f. a high voltage switching power driver including a high voltage current booster connected between said pair of terminal busses; g. means operatively associated with said low voltage switching control circuit operable to cause said low voltage switching control circuit to function as an input control sensor and to produce a sudden high speed transient drive to said high voltage power driver; h. a high voltage regenerative feedback power switching circuit connected between said pair of terminal busses; i. means operable to provide functional stability to said low voltage switching control circuit and said regenerative feedback power switching circuit, and including means for clamping said terminal bus voltages at predetermined values and for shunting unwanted thermal leakage currents to non-sensitive portions of the circuit; j. means operable to convert said regenerative feedback power switch to a high-voltage latching current-limited switch to produce sudden current pulses; and k. a degenerative feedback circuit connected between said regenerative feedback power switching circuit and one of said terminal busses and operable to counter the regenerative effect and limit the maximum amplitude of said current pulses to a predetermined value.
Claim 2
Dependent Claim
326 words
A control circuit for effecting an instantaneous voltage and current drive to an electrical power switching device to cause said power switching device to suddenly turn ON and latch in a conductive state, said control circuit comprising: a. a pair of external terminal busses of opposite polarity, one positive and one negative; b. an internal controlled power bus of polarity positive relative to said negative terminal bus; c. a current-limited voltage source connected at one end to said positive one of said pair of terminal busses; d. a voltage-limited voltage source connected at one end to said positive one of said pair of terminal busses and at the other end connected to said internal controlled power bus; e. a low-voltage switching control circuit connected between said internal controlled power bus and the negative polarity bus of said pair of terminal busses; f. a high voltage switching power driver including a high voltage current booster connected between said pair of terminal busses; g. means operatively associated with said low voltage switching control circuit operable to cause said low voltage switching control circuit to function as an input control sensor and to produce a sudden high speed transient drive to said high voltage power driver; h. a high voltage regenerative feedback power switching circuit connected between said pair of terminal busses; i. means operable to provide functional stability to said low voltage switching control circuit and said regenerative feedback power switching circuit, and including means for clamping said terminal bus voltages at predetermined values and for shunting unwanted thermal leakage currents to non-sensitive portions of the circuit; j. means operable to convert said regenerative feedback power switch to a high-voltage latching current-limited switch to produce sudden current pulses; and k. a degenerative feedback circuit connected between said regenerative feedback power switching circuit and one of said terminal busses and operable to counter the regenerative effect and limit the maximum amplitude of said current pulses to a predetermined value.
Claim 3
Dependent Claim
50 words
The combination according to claim 1, in which said current-limited voltage source is connected to said voltage-limited voltage source to provide a threshold voltage sensor operable to effect a low-voltage-point turn off of the voltage being supplied through said voltage-limited voltage source to produce a zero-voltage-switching action by said circuit.
Claim 4
Dependent Claim
20 words
The combination according to claim 1, in which said voltage-limited voltage source is connected to said low-voltage switching control circuit.
Claim 5
Dependent Claim
41 words
The combination according to claim 1, in which said low-voltage switching control circuit is connected to said high voltage power driver to clamp the input to said high voltage power driver to prevent unintentional output from said high voltage power driver.
Claim 6
Dependent Claim
44 words
The combination according to claim 1, in which said high voltage power driver includes a high voltage current booster connected to said high voltage regenerative power switch and constituting a high current input drive thereto to effect latching turn-on of said regenerative power switch.
Claim 7
Dependent Claim
44 words
The combination according to claim 1, in which said degenerative feedback circuit is connected in series with said regenerative power switch to reduce the regenerative action of said regenerative power switch to control the maximum amplitude of pulse current through said regenerative power switch.
Claim 8
Dependent Claim
40 words
The combination according to claim 1, in which said current-limited voltage source and said low-voltage switching control circuit are connected to said high voltage power driver and said regenerative power switch to prevent unintentional turn-on of said regenerative power switch.
Claim 9
Dependent Claim
155 words
The combination according to claim 1, in which said current-limited voltage source constitutes a voltage-limit threshold sensor and includes a non-linear resistor, first and second transistors each having base, collector and emitter terminals and a second resistor, said non-linear resistor being connected in parallel with the collector junction between the collector and base terminals of said first transistor, the emitter of said first transistor being connected to the base terminal of said second transistor, the collector terminal of said second transistor connected to the base terminal of said first transistor in feedback arrangement, said second resistor being connected in parallel with the emitter junction between the base and emitter terminals of said second transistor, and output means connected to the emitter terminal of said second transistor so that a current through the circuit from the collector of said first transistor to the emitter of said second transistor will be limited by a degenerative feedback action.
Claim 10
Dependent Claim
63 words
The combination according to claim 1, in which said current-limited voltage source comprises a depletion mode MOSFET resistor connected to said positive terminal bus, a current amplifier transistor connected to said positive terminal bus, a feedback transistor connected to said MOSFET resistor and said current amplifier transistor, and a current sensing feedback resistor connected to said current amplifier transistor and said feedback transistor.
Claim 11
Dependent Claim
37 words
The combination according to claim 1, in which said current-limited voltage source is connected to the positive end of a series diode string to provide an offset voltage proportional to the number of diodes in the string.
Claim 12
Dependent Claim
49 words
The combination according to claim 1, in which said voltage-limited voltage source comprises a depletion mode MOSFET resistor connected to said positive terminal bus, an amplifier transistor connected to said positive terminal bus and said internal controlled power bus, and a control transistor connected to said negative terminal bus.
Claim 13
Dependent Claim
103 words
The combination according to claim 1, in which said high voltage regenerative power switching circuit comprises a feedback latching transistor, a bypass resistor, an amplifier transistor, a shunting transistor, a feedback resistor, and a current sensing resistor, said feedback latching transistor being connected to said positive terminal bus, said bypass resistor, said amplifier transistor and said feedback resistor, while said bypass resistor is connected to said positive terminal bus, and said amplifier transistor is connected to said feedback resistor, said shunting transistor and said current sensing resistor, and said current sensing resistor and said shunting transistor are connected to said negative terminal bus.
Claim 14
Dependent Claim
63 words
The combination according to claim 1, in which said high voltage regenerative power switching circuit includes an amplifier transistor, a bypass resistor connected between the base of said transistor and the negative bus of said pair of busses, said bypass resistor cooperatively associated with another bypass resistor to control the sensitivity of the switching circuit and establish the threshold point for regenerative action.
Claim 15
Dependent Claim
138 words
The combination according to claim 1, in which a trigger control circuit is connected between said internal bus of positive polarity and the negative bus of said pair of busses, said trigger control circuit including a pair of input control terminals of opposite polarity and a buffer drive transistor, the positive terminal of said input control terminals being connected directly to said internal voltage bus, a transistor, a resistor, the value of which sets the input sensitivity of the trigger control circuit, the negative terminal of said input control terminals connecting to the base of said transistor and to said resistor, and a Schmitt trigger including a transistor, a second transistor, a common emitter resistor, a collector load resistor connected to the base of said second transistor, and a second collector load resistor connected to said buffer transistor.
Claim 16
Dependent Claim
58 words
The combination according to claim 10, in which the negative end of said diode string is connected to the other bus of said pair of busses, and a resistor is interposed between said diode string and said bus and operative to conduct leakage currents to prevent such leakage currents from interfering with other portions of the trigger circuit.
Claim 17
Dependent Claim
23 words
The combination according to claim 11, in which the emitter of said amplifier transistor is connected to said internal bus of positive polarity.
Claim 18
Dependent Claim
80 words
The combination according to claim 13, in which a shunting transistor is connected in parallel to said bypass resistor between the base node of said amplifier transistor and the negative power terminal bus of said pair of busses, said shunting transistor when in conduction shunting all node currents to the negative power terminal bus and clamping the nodal voltage to prevent the regenerative circuit from spontaneously turning ON from the effects of thermal leakage currents or dV/dt induced node current.
Claim 19
Dependent Claim
106 words
The combination according to claim 13, in which a buffer drive transistor is connected between the positive bus of said pair of busses and the base node of said amplifier transistor, a resistor connected between the base and emitter of said buffer drive transistor to bypass thermal leakage currents to prevent accidental drive to the regenerative switching circuit, and a clamping transistor connected to the base node of said buffer drive transistor and when in conduction clamping the base node of the buffer drive transistor to further reduce the possibility of thermal leakage current or dV/dt induced current being amplified and delivered to said switching circuit.
Claim 20
Dependent Claim
95 words
The combination according to claim 14, in which said trigger control system includes a resistor connected to the collector of the buffer transistor to limit the current drawn thereby, a pair of clamping transistors normally in an OFF condition, a diode connected to the emitter of the buffer transistor to provide an offset threshold voltage before current is delivered to the clamping transistors, a bleeder resistor operative to keep minor leakage currents from reaching the clamping transistors, and a pair of current sharing resistors connected from one diode to the base of the clamping transistors.
Claim 21
Dependent Claim
42 words
The combination according to claim 14, in which said trigger control system includes a phototransistor operative to conduct current between the internal bus and the base of a bias transistor to effect adequate current drive to the input of the control circuit.
Claim 22
Dependent Claim
26 words
The combination according to claim 14, in which a bleeder transistor is provided connected between the base node of the phototransistor and the negative terminal bus.
Claim 23
Dependent Claim
76 words
The combination according to claim 1, in which said input control sensor circuit includes negative and positive input control terminals, a resistor connected between the positive input terminal and said internal voltage bus, and a transistor having its base node connected to said positive input terminal and its emitter connected to the input node of the Schmitt trigger and through a resistor to the negative input terminal and the negative bus of said pair of busses.
Claim 24
Dependent Claim
187 words
The combination according to claim 1, in which said current-limited voltage source includes a current-limited resistor, an amplifier transistor, said current-limited resistor being arranged to conduct current to the base of the amplifier transistor to provide a low impedance current/voltage source at the emitter node of said amplifier transistor having a current capability greater than the limited current of the current-limited resistor, a second transistor, a feedback resistor, and a pair of controlled output terminals of opposite polarity, the positive terminal of the pair being connected directly to the emitter of said second transistor and being connected through said feedback resistor to the emitter of said amplifier transistor whereby when the amplitude of the current through the feedback resistor is sufficient the base-emitter junction of the second transistor begins to conduct and a collector-emitter current is conducted through the second transistor bypassing the base-emitter junction of the amplifier transistor and shunting the current through the current limited resistor away from the base of the amplifier transistor to the degree that an equilibrium is established and a nominally constant current is then supplied at the controlled output terminals.
Claim 25
Dependent Claim
52 words
The combination according to claim 23, in which a shunting transistor is provided to effect reduction or turnoff of the voltage at the output terminals, said shunting transistor having its emitter connected to the negative bus of said pair of busses and its collector connected to the base of said amplifier transistor.
Claim 26
Dependent Claim
260 words
A phase-controlled trigger circuit, comprising: a. a pair of external busses of opposite polarity; b. an internal bus of positive polarity; C. a voltage-limited voltage source connected to one of said pair of external busses, said voltage-limited voltage source including a control transistor the c. a of which is connected to the negative external bus; d. a diode string connected between the internal bus of positive polarity and the base node of said control transistor; e. a low-voltage switching control circuit connected between said voltage-limited voltage source and the other bus of said pair of external busses; f. a high voltage power driver including a high voltage current booster connected between said pair of external busses; g. means operatively associated with said low voltage switching control circuit operable to cause said low voltage switching control circuit to function as an input control sensor and high speed trigger drive for said high voltage power driver; h. a high voltage regenerative power switching circuit connected between said pair of external busses; i. means operable to provide functional stability to said low voltage switching control circuit and including means for clamping voltages at predetermined values and for shunting unwanted thermal leakage currents; j. means operable to convert said regenerative feedback power switch to a high voltage latching current-limited switch to produce sudden current pulses; and k. a degenerative feedback circuit connected between said regenerative feedback power switching circuit and one of said busses and operable to counter the regenerative effect and limit the maximum amplitude of said current pulses to a predetermined value.
Claim 27
Dependent Claim
260 words
A phase-controlled trigger circuit, comprising: a. a pair of external busses of opposite polarity; b. an internal bus of positive polarity; C. a voltage-limited voltage source connected to one of said pair of external busses, said voltage-limited voltage source including a control transistor the c. a of which is connected to the negative external bus; d. a diode string connected between the internal bus of positive polarity and the base node of said control transistor; e. a low-voltage switching control circuit connected between said voltage-limited voltage source and the other bus of said pair of external busses; f. a high voltage power driver including a high voltage current booster connected between said pair of external busses; g. means operatively associated with said low voltage switching control circuit operable to cause said low voltage switching control circuit to function as an input control sensor and high speed trigger drive for said high voltage power driver; h. a high voltage regenerative power switching circuit connected between said pair of external busses; i. means operable to provide functional stability to said low voltage switching control circuit and including means for clamping voltages at predetermined values and for shunting unwanted thermal leakage currents; j. means operable to convert said regenerative feedback power switch to a high voltage latching current-limited switch to produce sudden current pulses; and k. a degenerative feedback circuit connected between said regenerative feedback power switching circuit and one of said busses and operable to counter the regenerative effect and limit the maximum amplitude of said current pulses to a predetermined value.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |