US3988649A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal amplitude monitor and relay driver circuit
Assignee: General Electric Co
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Filing: 1975-02-10
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Granted: 1976-10-26
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Expires: 1995-02-10
Abstract
Abstract A signal amplitude monitor and relay driver circuit. The input signal is applied to a plurality of diodes connected in series with a set of normally closed relay contacts and a first resistor. A second resistor is connected in parallel with the series connected diodes through a set of normally open contacts of the relay. A third resistor is connected in parallel with the combination of the first resistor and normally closed contacts. A transistor circuit is connected with its emitter-base circuit responsive to the signal developed across the first resistor. The transistor output drives an amplifier which energizes the relay coil. When the normally closed contacts are closed the input signal must exceed a first predetermined level before the transistor circuit becomes conductive causing the amplifier to energize the relay coil. When the relay operates the first resistor is taken out of the circuit because the normally closed contacts open, and the second resistor is connected in the circuit because the normally open contacts close. Under these conditions the transistor circuit will remain conductive until the input signal falls below a second predetermined level, the second predetermined level being lower than the first predetermined level.
Inventors
- 👤 Sandor Mentler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:52
CPC Classifications
H; H01; H01H; H01H47/00; H01H47/22; H01H47/32
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
183 words
A circuit for operating a relay in response to an input signal comprising: a. a plurality of diodes connected in series with a first resistor and normally closed contacts of the relay, said series combination being driven by the input signal; b. a second resistor connected in parallel with the series connected diodes through normally open contacts of the relay; c. a third resistor connected in parallel circuit with the combination of the first resistor and normally closed contacts; d. a transistor circuit having its emitter-base circuit responsive to the signal developed across the thrid resistor, said series connected diodes being poled to conduct current through said emitter-base circuit, said transistor becoming conductive when the normally closed contacts are closed and the input signal exceeds a first predetermined magnitude, but becoming nonconductive when the normally open contacts are closed and the input signal falls below a second predetermind level, less than the first predetermined level; and e. circuit means responsive to the transistor circuit output for energizing the relay when the transistor is conductive and deenergizing the relay when the transistor is nonconductive.
Claim 2
Dependent Claim
183 words
A circuit for operating a relay in response to an input signal comprising: a. a plurality of diodes connected in series with a first resistor and normally closed contacts of the relay, said series combination being driven by the input signal; b. a second resistor connected in parallel with the series connected diodes through normally open contacts of the relay; c. a third resistor connected in parallel circuit with the combination of the first resistor and normally closed contacts; d. a transistor circuit having its emitter-base circuit responsive to the signal developed across the thrid resistor, said series connected diodes being poled to conduct current through said emitter-base circuit, said transistor becoming conductive when the normally closed contacts are closed and the input signal exceeds a first predetermined magnitude, but becoming nonconductive when the normally open contacts are closed and the input signal falls below a second predetermind level, less than the first predetermined level; and e. circuit means responsive to the transistor circuit output for energizing the relay when the transistor is conductive and deenergizing the relay when the transistor is nonconductive.
Claim 3
Dependent Claim
215 words
A circuit for operating an electromagnetic relay between picked-up and dropped-out positions which comprises: a. a pair of signal input terminals, b. a plurality of diodes connected in series circuit relation between said input terminals, said series circuit providing an intermediate terminal defining serially adjacent sections of a voltage divider including said diodes, c. a pair of shunt circuits alternately completed by said relay in its picked-up and dropped-out positions to connect first and second shunting resistors across said voltage divider sections respectively, a first said shunting resistor being of substantially smaller magnitude than the other said shunting resistor and being connected across a first section of said voltage divider when said relay is in said dropped-out position, d. a third resistor connected across said first section of said voltage divider, said third resistor being of substantially greater magnitude than said first shunting resistor, and e. transistor means having an emitter-base circuit connected across said third resistor and an output circuit connected to energize said relay, f. said voltage divider and alternate shunting circuits being operable to initiate transistor output current in response to a first high level of input signal and to maintain said transistor output current over a range of input signal levels between said high level and a second discretely lower level.
Claim 4
Dependent Claim
215 words
A circuit for operating an electromagnetic relay between picked-up and dropped-out positions which comprises: a. a pair of signal input terminals, b. a plurality of diodes connected in series circuit relation between said input terminals, said series circuit providing an intermediate terminal defining serially adjacent sections of a voltage divider including said diodes, c. a pair of shunt circuits alternately completed by said relay in its picked-up and dropped-out positions to connect first and second shunting resistors across said voltage divider sections respectively, a first said shunting resistor being of substantially smaller magnitude than the other said shunting resistor and being connected across a first section of said voltage divider when said relay is in said dropped-out position, d. a third resistor connected across said first section of said voltage divider, said third resistor being of substantially greater magnitude than said first shunting resistor, and e. transistor means having an emitter-base circuit connected across said third resistor and an output circuit connected to energize said relay, f. said voltage divider and alternate shunting circuits being operable to initiate transistor output current in response to a first high level of input signal and to maintain said transistor output current over a range of input signal levels between said high level and a second discretely lower level.
Claim 5
Dependent Claim
66 words
A circuit as recited in claim 2 wherein the input signal is a plurality of regularly recurring pulses and wherein a capacitor is connected in parallel circuit relation with said voltage divider, said capacitor maintaining said transistor output current for a time sufficient to maintain the relay in the picked-up position as long as the amplitude of the recurring pulses exceeds said second low signal level.
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) | 1979-10-26 | 1980-04-26 | 1980-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-26 | 1984-04-26 | 1984-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-26 | 1988-04-26 | 1988-10-26 | $7700.00 | Window Closed / Lapsed |