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US 4,144,552 AGranted
Sequential timing circuitry
OwnerDan Sibalisinventor
Life of this patent
Estimating the term…
Abstract
Improved sequential timing circuitry includes a relay coil, normally closed of form C relay contacts and a relay latching element, e.g., a resistor limiting relay coil current to a value intermediate pull-in and holding limit, serially connected to a high ripple D.C. source. A delay circuit selectively gates on a controlled switch to activate the relay, thereby advancing circuit operation to a next sequential task. In accordance with varying aspects of the present invention, the circuitry of the instant invention may be employed to sequentially excite plural relays with differing delay periods, or to delay turn-on of a master relay, as in a motor control application.
Claims14
In combination, a source of direct current energy;
- a relay including a relay actuating coil characterized by a minimum pull-in current required to energize said relay and a maximum holding current required to maintain an already activated relay in an energized state, normally closed relay contacts, relay latching means, said relay latching means, relay coil and normally closed contacts being serially connected and connected to said direct current source, controlled switch means having a control port and a normally nonconductive conduction path connected in parallel with said relay latching means, and delay means connected to said control port of said controlled switch means for energizing said controlled switch means after effecting a timing delay, wherein said relay further includes normally open contacts, and means including said normally open contacts selectively connecting said source of direct current energy with said relay coil.
In combination, a source of direct current energy;
- a relay including a relay actuating coil characterized by a minimum pull-in current required to energize said relay and a maximum holding current required to maintain an already activated relay in an energized state, normally closed relay contacts, relay latching means, said relay latching means, relay coil and normally closed contacts being serially connected and connected to said direct current source, controlled switch means having a control port and a normally nonconductive conduction path connected in parallel with said relay latching means, and delay means connected to said control port of said controlled switch means for energizing said controlled switch means after effecting a timing delay, wherein said controlled switch means comprises a silicon controlled rectifier, and wherein said delay means comprises a relaxation oscillator having a resistance-capacitance timing network and an output connected to the gate terminal of said silicon control rectifier.
In combination, a source of direct current energy;
- a relay including a relay actuating coil characterized by a minimum pull-in current required to energize said relay and a maximum holding current required to maintain an already activated relay in an energized state, normally closed relay contacts, relay latching means, said relay latching means, relay coil and normally closed contacts being serially connected and connected to said direct current source, controlled switch means having a control port and a normally nonconductive conduction path connected in parallel with said relay latching means, and delay means connected to said control port of said controlled switch means for energizing said controlled switch means after effecting a timing delay, wherein said relay latching means comprises a resistor characterized by resistance value limiting the quiescent current through said relay coil to a value intermediate said minimum pull-in current and maximum holding current.
In combination, a source of direct current energy;
- a relay including a relay actuating coil characterized by a minimum pull-in current required to energize said relay and a maximum holding current required to maintain an already activated relay in an energized state, normally closed relay contacts, relay latching means, said relay latching means, relay coil and normally closed contacts being serially connected and connected to said direct current source, controlled switch means having a control port and a normally nonconductive conduction path connected in parallel with said relay latching means, and delay means connected to said control port of said controlled switch means for energizing said controlled switch means after effecting a timing delay, wherein said relay further includes normally open contacts, and further comprising an additional relay including a relay coil and normally closed contacts, additional relay latching means, said additional relay coil and said normally closed contacts of said additional relay being serially connected together and connected to said normally open contacts of said relay.
In combination, a source of direct current energy;
- a relay including a relay actuating coil characterized by a minimum pull-in current required to energize said relay and a maximum holding current required to maintain an already activated relay in an energized state, normally closed relay contacts, relay latching means, said relay latching means, relay coil and normally closed contacts being serially connected and connected to said direct current source, controlled switch means having a control port and a normally nonconductive conduction path connected in parallel with said relay latching means, and delay means connected to said control port of said controlled switch means for energizing said controlled switch means after effecting a timing delay, further comprising a source of alternating current potential, additional relay means including a relay coil and a normally open latching contacts, said coil and said latching contacts of said additional relay being serially connected across said source of alternating current potential, and means connecting said source of direct current energy in parallel with said additional relay latching contacts, said coil of said additional relay being serially connected across said source of alternating current potential, and means connecting said source of direct current energy in parallel with said additional relay latching contacts said coil of said minimum pull-in current of said relay coil.
Dependencies are inferred from the claim text.