US3774082A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Time interlock for air conditioning compressor and the like
Assignee: CAM STAT Inc
•
Filing: 1972-10-18
•
Granted: 1973-11-20
•
Expires: 1992-10-18
Abstract
Abstract A circuit for controlling a load, such as the cooling compressor of an air conditioner, to prevent short cycling. A circuit which provides a time delay or interlock after de-energizing a load, before the load can again be energized. A circuit operable to connect a load and a storage capacitor to a power source in response to external switch closure, and on opening of the switch, to disconnect the load and utilize the charged capacitor to block for a period of time, further load switching regardless of external switch operation.
Inventors
- 👤 T Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:41
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/08; H02H7/0816; H02H11/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
192 words
In a circuit for energizing a load from a power source by a control switch not less than a predetermined time after deenergization of the load, the combination of: switching means operable between first and second conditions; a control unit for said switching means; a storage circuit; a discharge circuit for said storage circuit; with said switching means when in said second condition connecting said storage circuit to the power source through the control switch for charging said storage circuit from the power source when the control switch is closed, and connecting the load to the power source through the control switch for energizing the load; and circuit means connecting said storage circuit to said control unit for maintaining said switching means in said first condition when said storage circuit is charged to a predetermined value and said switching means has switched to said first condition; with said switching means switching to said first condition when the control switch is opened disconnecting the power source and with said storage circuit discharging through said discharge circuit and blocking actuation of said switching means to said second condition until discharged to a predetermined value.
Claim 2
Dependent Claim
192 words
In a circuit for energizing a load from a power source by a control switch not less than a predetermined time after deenergization of the load, the combination of: switching means operable between first and second conditions; a control unit for said switching means; a storage circuit; a discharge circuit for said storage circuit; with said switching means when in said second condition connecting said storage circuit to the power source through the control switch for charging said storage circuit from the power source when the control switch is closed, and connecting the load to the power source through the control switch for energizing the load; and circuit means connecting said storage circuit to said control unit for maintaining said switching means in said first condition when said storage circuit is charged to a predetermined value and said switching means has switched to said first condition; with said switching means switching to said first condition when the control switch is opened disconnecting the power source and with said storage circuit discharging through said discharge circuit and blocking actuation of said switching means to said second condition until discharged to a predetermined value.
Claim 3
Dependent Claim
24 words
A circuit as defined in claim 1 wherein said switching means when in said first condition includes a shunting connection across said storage circuit.
Claim 4
Dependent Claim
54 words
A circuit as defined in claim 1 wherein said switching means includes a transistor connected across the power source and normally biased into conduction to said second condition by said control unit when the control switch is closed, with said storage circuit blocking said conduction for a time after the control switch is opened.
Claim 5
Dependent Claim
57 words
A circuit as defined in claim 1 wherein said storage circuit includes a capacitor connected across the power source for charging through said discharge circuit when said switching means is in said second condition and connected across said discharge circuit when said switching means switches to said first condition, providing a voltage change at said control unit.
Claim 6
Dependent Claim
39 words
A circuit as defined in claim 4 wherein said control unit includes a transistOr with the bias thereof provided through said capacitor, with said transistor when biased to nonconduction preventing said switching means from switching to said second condition.
Claim 7
Dependent Claim
163 words
In a circuit for energizing a load from a power source by a control switch not less than a predetermined time after de-energization of the load, the combination of: a first transistor; a storage capacitor connected between a first point and the gate of said first transistor; a resistor and a rectifier connected in parallel between a second point and the gate of said first transistor; circuit means connecting said first and second points across the power source through the control switch; and switching means controlled by said first transistor for switching between first and second conditions and including means connecting said first point to said second point when in said first condition and connecting the load to said second point when in said second condition, with said capacitor charging when the control switch is closed and said switching means is in said second condition and discharging when the control switch is opened and said switching means is changed to said first condition.
Claim 8
Dependent Claim
163 words
In a circuit for energizing a load from a power source by a control switch not less than a predetermined time after de-energization of the load, the combination of: a first transistor; a storage capacitor connected between a first point and the gate of said first transistor; a resistor and a rectifier connected in parallel between a second point and the gate of said first transistor; circuit means connecting said first and second points across the power source through the control switch; and switching means controlled by said first transistor for switching between first and second conditions and including means connecting said first point to said second point when in said first condition and connecting the load to said second point when in said second condition, with said capacitor charging when the control switch is closed and said switching means is in said second condition and discharging when the control switch is opened and said switching means is changed to said first condition.
Claim 9
Dependent Claim
47 words
A circuit as defined in claim 6 wherein said switching means includes relay means with single pole double throw contact means and actuating element, and a second current control transistor in series with said element across the power source, with said first transistor controlling said second transistor.
Claim 10
Dependent Claim
41 words
A circuit as defined in claim 7 wherein the power source is an A.C. source, and including a rectifier-filter circuit for connection between the power source and said first and second points providing D.C. power for said capacitor and switching means.
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) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |