US3628099A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resistance-responsive control circuit
Assignee: Cooper Industries LLC
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Filing: 1970-06-17
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Granted: 1971-12-14
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Expires: 1990-06-17
Abstract
Abstract A circuit for controlling energization and deenergization of a load only in response to a value of resistance falling within a narrow predetermined range of resistances. The circuit has the capability of preventing unlocking by the insertion of a variable resistor between the terminals provided for sensing the keying resistance and hunting for the proper value of resistance.
Inventors
- 👤 Carl E Atkins
- 👤 Arthur F Cake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:32
CPC Classifications
G; G07; G07C; G07C9/00; G07C9/00174; G07C9/00658; G07C9/00714; B; B60; B60R; B60R25/00; B60R25/01; B60R25/04; Y; Y10; Y10S; Y10S70/00; Y10S70/46
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
119 words
A resistance-responsive circuit for controlling the energization and deenergization of a load comprising: 1. sensing circuit means having a pair of input terminals and operative to generate a predetermined output voltage in response to the connection of a keying resistance between said input terminals; 2. first, second and third signal-generating circuit means, each operative in response to said predetermined output voltage to generate first, second and third predetermined output signals, respectively; and 3. signal-responsive circuit means having first, second and third input channels and being operative to alter the energization state of a load only in response to the coincident application of said first, second and third predetermined output signals to said first, second and third input channels, respectively.
Claim 2
Dependent Claim
119 words
A resistance-responsive circuit for controlling the energization and deenergization of a load comprising: 1. sensing circuit means having a pair of input terminals and operative to generate a predetermined output voltage in response to the connection of a keying resistance between said input terminals; 2. first, second and third signal-generating circuit means, each operative in response to said predetermined output voltage to generate first, second and third predetermined output signals, respectively; and 3. signal-responsive circuit means having first, second and third input channels and being operative to alter the energization state of a load only in response to the coincident application of said first, second and third predetermined output signals to said first, second and third input channels, respectively.
Claim 3
Dependent Claim
27 words
first, second and third signal-generating circuit means, each operative in response to said predetermined output voltage to generate first, second and third predetermined output signals, respectively; and
Claim 4
Dependent Claim
27 words
first, second and third signal-generating circuit means, each operative in response to said predetermined output voltage to generate first, second and third predetermined output signals, respectively; and
Claim 5
Dependent Claim
13 words
A resistance-responsive circuit according to claim 1 wherein said signal-responsive circuit means comprises:
Claim 6
Dependent Claim
37 words
charging circuit means comprising a resistance and a first capacitance connected in series, said first capacitance being dischargeable by said first AND gate when coincident signals are provided to said first, second and third input channels; and
Claim 7
Dependent Claim
37 words
charging circuit means comprising a resistance and a first capacitance connected in series, said first capacitance being dischargeable by said first AND gate when coincident signals are provided to said first, second and third input channels; and
Claim 8
Dependent Claim
17 words
a third AND gate controlled by said first AND gate and by said third signal-generating circuit means;
Claim 9
Dependent Claim
17 words
a third AND gate controlled by said first AND gate and by said third signal-generating circuit means;
Claim 10
Dependent Claim
20 words
output switching means operative to change its conductivity state in response to Said intermediate output of said threshold circuit means.
Claim 11
Dependent Claim
20 words
output switching means operative to change its conductivity state in response to Said intermediate output of said threshold circuit means.
Claim 12
Dependent Claim
24 words
said threshold circuit means of said second signal-generating circuit means includes variable bias means set to maintain said threshold circuit means normally conducting; and
Claim 13
Dependent Claim
24 words
said threshold circuit means of said second signal-generating circuit means includes variable bias means set to maintain said threshold circuit means normally conducting; and
Claim 14
Dependent Claim
43 words
second signal-generating circuit means normally operative to generate a second predetermined output signal, and further operative in response to a second predetermined minimum input voltage greater than said first predetermined minimum input voltage to cease generation of said second predetermined output signal; and
Claim 15
Dependent Claim
43 words
second signal-generating circuit means normally operative to generate a second predetermined output signal, and further operative in response to a second predetermined minimum input voltage greater than said first predetermined minimum input voltage to cease generation of said second predetermined output signal; and
Claim 16
Dependent Claim
43 words
signal-responsive circuit means having first and second input channels and being operative to alter the energization state of a load only in response to the coincident application of said first and second predetermined output signals to said first and second input channels, respectively.
Claim 17
Dependent Claim
43 words
signal-responsive circuit means having first and second input channels and being operative to alter the energization state of a load only in response to the coincident application of said first and second predetermined output signals to said first and second input channels, respectively.
Claim 18
Dependent Claim
46 words
said threshold circuit means of said third signal-generating circuit means includes bias circuit means operative to maintain said threshold circuit means nonconductive and to enable said threshold circuit means to be rendered conductive by virtually any decrease in the normal output of said sensing circuit means.
Claim 19
Dependent Claim
46 words
said threshold circuit means of said third signal-generating circuit means includes bias circuit means operative to maintain said threshold circuit means nonconductive and to enable said threshold circuit means to be rendered conductive by virtually any decrease in the normal output of said sensing circuit means.
Claim 20
Dependent Claim
28 words
relaxation oscillator circuit means comprising a normally discharged during periods of oscillation of said relaxation oscillator circuit means, charging being controlled by said third signal-generating circuit means; and
Claim 21
Dependent Claim
28 words
relaxation oscillator circuit means comprising a normally discharged during periods of oscillation of said relaxation oscillator circuit means, charging being controlled by said third signal-generating circuit means; and
Claim 22
Dependent Claim
67 words
A resistance-responsive circuit according to claim 2 including antitamper circuit means coupled to each of said first, second and third signal-generating circuit means and operative for a predetermined period of time after actuation by connecting of a nonkeying resistance between said input terminals to prevent said signal-responsive circuit means from changing the energization state of a load when a keying resistance is connected between said input terminals.
Claim 23
Dependent Claim
46 words
signal-responsive circuit means having first, second and third input channels and being operative to alter the energization state of a load only in response to the coincident application of said first, second and third predetermined output signals to said first, second and third input channels, respectively.
Claim 24
Dependent Claim
46 words
signal-responsive circuit means having first, second and third input channels and being operative to alter the energization state of a load only in response to the coincident application of said first, second and third predetermined output signals to said first, second and third input channels, respectively.
Claim 25
Dependent Claim
28 words
semiconductor switching means operative to control the energization state of a load, being maintained normally nonconductive by the voltage developed across said capacitance of said charging circuit means.
Claim 26
Dependent Claim
28 words
semiconductor switching means operative to control the energization state of a load, being maintained normally nonconductive by the voltage developed across said capacitance of said charging circuit means.
Claim 27
Dependent Claim
14 words
A resistance-responsive control circuit according to claim 3 wherein said antitamper circuit means comprises:
Claim 28
Dependent Claim
49 words
a normally charged third capacitance connected in a parallel charging current path with said second capacitance and to a normally open discharge current path controlled by said second AND gate which is operative to close said discharging current path when a nonkeying resistance is connected between said input terminals.
Claim 29
Dependent Claim
49 words
a normally charged third capacitance connected in a parallel charging current path with said second capacitance and to a normally open discharge current path controlled by said second AND gate which is operative to close said discharging current path when a nonkeying resistance is connected between said input terminals.
Claim 30
Dependent Claim
27 words
A resistance-responsive circuit according to claim 1 wherein said sensing circuit means consists of a two-stage emitter-follower amplifier having a high input impedance at said input terminals.
Claim 31
Dependent Claim
40 words
A resistance-responsive circuit according to claim 1 wherein each of said signal-generating means includes a normally conducting output transistor which provides said predetermined output signal by becoming nonconductive in response to said predetermined output voltage of said sensing circuit means.
Claim 32
Dependent Claim
15 words
A resistance-responsive circuit according to claim 1 wherein each of said signal-generating circuit means comprises:
Claim 33
Dependent Claim
33 words
A resistance-responsive circuit according to claim 7 wherein: 1 . said threshold circuit means of said first signal-generating circuit means includes variable bias means set to maintain said threshold circuit means normally nonconducting;
Claim 34
Dependent Claim
13 words
A control circuit for controlling the energization and deenergization of a load comprising;
Claim 35
Dependent Claim
13 words
A control circuit for controlling the energization and deenergization of a load comprising;
Claim 36
Dependent Claim
46 words
A control circuit according to claim 9 and further including a voltage divider circuit comprising a fixedly connected resistor and a selectively connectable keying resistor operative in combination to provide at their junction an input voltage falling between said first and second predetermined minimum input voltages.
References Cited (Backward Citations)
US3159772A
Cited
US3136307A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-13 | 1975-06-14 | 1975-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-13 | 1979-06-14 | 1979-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-13 | 1983-06-14 | 1983-12-14 | $7700.00 | Window Closed / Lapsed |