US3581114A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scr slaving circuit
Assignee: Motorola Solutions Inc
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Filing: 1968-09-03
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Granted: 1971-05-25
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Expires: 1988-09-03
Abstract
Abstract An SCR slaving circuit wherein first and second controlled rectifiers are connected in parallel with each other and are further connected in series with a load across an AC line. A control signal is coupled to the gate electrode of the first controlled rectifier to control the slaving action in the circuit, and rectifier control circuitry is coupled between one side of the AC line and the gate electrode of the second controlled rectifier. The rectifier control circuitry blocks gate current to the second controlled rectifier on one-half cycle of the AC line voltage and thereafter provides gate current to turn on the second controlled rectifier. The second controlled rectifier will turn on the following half-cycle of the AC line voltage provided that the first controlled rectifier was conducting the previous half-cycle of the AC line voltage.
Inventors
- 👤 Robert E Gregson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:28
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/13; H03K17/136; H02; H02M; H02M1/00; H02M1/08; H02M1/083
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
143 words
An AC control circuit including, in combination: a first controlled rectifier connected in series with a load between circuit input terminals which are adapted for connection to a source of AC line voltage, a second controlled rectifier poled opposite to and connected in parallel with said first controlled rectifier, and rectifier control means including a capacitor connected to a gate electrode of said second controlled rectifier and responsive to one-half cycle of AC line voltage to cause charging of said capacitor and to block gate current to said second controlled rectifier during substantially all of said half-cycle, said rectifier control means further responsive to another half-cycle of AC voltage to discharge said capacitor to provide gate current to said second controlled rectifier to drive same into conduction, whereby said first and second controlled rectifiers conduct on alternate half-cycles of the AC line voltage.
Claim 2
Dependent Claim
143 words
An AC control circuit including, in combination: a first controlled rectifier connected in series with a load between circuit input terminals which are adapted for connection to a source of AC line voltage, a second controlled rectifier poled opposite to and connected in parallel with said first controlled rectifier, and rectifier control means including a capacitor connected to a gate electrode of said second controlled rectifier and responsive to one-half cycle of AC line voltage to cause charging of said capacitor and to block gate current to said second controlled rectifier during substantially all of said half-cycle, said rectifier control means further responsive to another half-cycle of AC voltage to discharge said capacitor to provide gate current to said second controlled rectifier to drive same into conduction, whereby said first and second controlled rectifiers conduct on alternate half-cycles of the AC line voltage.
Claim 3
Dependent Claim
99 words
The combination defined in claim 1 wherein said rectifier control means includes: a diode coupled to one of said input terminals, said capacitor connected between said diode and said first controlled rectifier, said capacitor charging up to a predetermined voltage on one-half cycle of the AC line voltage and reverse biasing said diode, and a semiconductor device having input, output and control electrodes, said semiconductor device connected between said capacitor and said second controlled rectifier and operative to discharge said capacitor and fire said second controlled rectifier when the AC line voltage initially forward biases said second controlled rectifier.
Claim 4
Dependent Claim
48 words
The combination defined in claim 2 wherein said diode is connected between the input and control electrodes of said semiconductor device and maintains said semiconductor device cutoff until said second controlled rectifier has been conducting for a previous half-cycle and the AC line voltage reaches a predetermined magnitude.
Claim 5
Dependent Claim
42 words
The combination defined in claim 3 which further includes a current limiting resistor connected between said one of said input terminals and said diode for limiting the base drive to said semiconductor device and for controlling the charging time of the capacitor.
Claim 6
Dependent Claim
108 words
The combination defined in claim 4 wherein: said semiconductor device is a transistor, said load is connected between said one input terminal and a common junction of the anode of said first controlled rectifier and the cathode of said second controlled rectifier, said capacitor discharging through the emitter-base junction of said transistor, through said current limiting resistor and through said load upon reaching a predetermined charging voltage, said capacitor thereafter discharging through the emitter-collector path of said transistor and into the gate electrode of said second controlled rectifier to fire said second controlled rectifier when the AC line voltage initially goes positive anode-to-cathode of said second controlled rectifier.
References Cited (Backward Citations)
US3388269A
Cited
US3458732A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |