Controller for video tape recorder

• US 4,096,542 A
• Filed: 03/28/1977
• Issued: 06/20/1978
• Est. Priority Date: 03/28/1977
• Status: Expired due to Term

• Current Assignee: Zenith Radio Corporation (LG Corporation)
• Original Assignee: Zenith Radio Corporation (LG Corporation)
• Inventors: Rennick, John L., Pappas, Frank
• Primary Examiner(s): Salce, Patrick R.
• Application Number:
  US05/781,611
• Time in Patent Office: 449 Days
• Field of Search: 361/93, 361/196, 361/187, 307/141, 307/293, 328/129, 325/396, 325/492, 358/190, 358/296, 358/301, 360/69, 360/74, 360/81, 360/137, 346/107 A
• US Class Current: 361/196
• CPC Class Codes: H02H 3/12 responsive to underload or no-load for motors H02H7/0827

Abstract

A controller for initiating operation of a video tape recorder and for terminating operation when its power consumption drops to a predetermined level utilizes a power transfer circuit for coupling the recorder to a source of energizing potential. A normally open switch, included in the transfer circuit, responds to an actuating signal developed by an operational amplifier, which amplifier is activated by an enabling signal from a preset clock. Thereafter, the amplifier is controlled by a derived signal having an amplitude proportional to the current drawn by the recorder. When the energizing current for the recorder drops below a predetermined level, the derived control signal is now of insufficient amplitude to maintain the amplifier in an operating condition, as a result, the actuating signal for switch is interrupted and operation of the recorder is terminated.

Claims

1. A controller for initiating operation of an electrically energized apparatus and for terminating operation of that apparatus, in response to a reduction in its power consumption to a predetermined level, said controller comprising:

a source of enabling signal;

a power transfer circuit for coupling said apparatus to a source of energizing potential;

normally-open switch means included in said power transfer circuit and responsive to an actuating signal for closing said switch to activate said power transfer circuit and thereby energize said apparatus;

a current transformer comprising a primary winding included in said power transfer circuit and a secondary winding;

means coupled to said secondary winding for developing a control signal having an amplitude proportional to the current drawn by said apparatus;

a signal comparator having a first input circuit coupled to said source of enabling signal and to said control signal developing means, and also having a fixed bias second input circuit,

said comparator further having an output circuit, coupled to said switch means, for establishing a switch actuating signal upon receipt by said first input circuit of an enabling signal having an amplitude sufficient to overcome the fixed bias on said second input circuit, for maintaining said actuating signal during application of said control signal to said first input circuit and for terminating said actuating signal when said control signal drops below the value of fixed bias on said second input circuit.

2. A controller in accordance with claim 1 which further includes means, coupled to said control signal developing means, for delaying for a predetermined period of time upon occurrence of said reduction of power consumption, the decay of said control signal to a level below the bias on said second input circuit.

3. A controller in accordance with claim 1 in which said signal comparator comprises an operational amplifier.

4. A controller in accordance with claim 1 in which said means for developing said control signal comprises a rectifier circuit.

5. A controller for initiating operation of an electrically energized apparatus at a preset time and for terminating operation of that apparatus in response to a reduction in its power consumption to a predetermined level, said controller comprising:

a presettable clock comprising means for developing at a preset time, an enabling signal, said means including an input terminal and an output terminal;

a power transfer circuit for coupling said apparatus to a source of energizing potential;

a normally-open switch means included in said power transfer circuit and responsive to an actuating signal for closing said switch to activate said power transfer circuit and thereby energize said apparatus;

a current transformer comprising a primary winding included in said power transfer circuit and a secondary winding;

means coupled to said secondary winding for developing a control signal having an amplitude proportional to the current drawn by said apparatus;

a signal comparator comprising a first input circuit coupled to said clock output terminal and to said control signal developing means,

a fixed bias second input circuit,

a first output circuit, coupled to said switch means, for establishing a switch actuating signal upon receipt, by said first input circuit, of an enabling signal having an amplitude that exceeds the bias on said second input circuit, for maintaining said actuating signal during application of said control signal to said first input circuit and for terminating said actuating signal when said control signal drops below the value of fixed bias on said second input circuit,

said signal comparator further comprising a second output circuit for deriving, subsequent in time to the developing of said control signal, a disabling signal; and

means for coupling said disabling signal to said clock input terminal to defeat said enabling signal.