Power-up circuit for microprocessor based appliance control

• US 4,381,459 A
• Filed: 09/25/1981
• Issued: 04/26/1983
• Est. Priority Date: 09/25/1981
• Status: Expired due to Fees

• Current Assignee: Maytag Corporation (Whirlpool Corporation)
• Original Assignee: Maytag Corporation (Whirlpool Corporation)
• Inventors: Cotton, Curran D.
• Primary Examiner(s): Gellner, Michael L.
• Assistant Examiner(s): DEBOER, TODD
• Application Number:
  US06/305,559
• Time in Patent Office: 578 Days
• Field of Search: 307/86, 307/139, 307/142, 364/707
• US Class Current: 307/139
• CPC Class Codes: G05B 19/0428 Safety, monitoring G05B19/0423 takes precedence
• CPC Class Codes: G05B 2219/21163 Test I-O if functional or safe value
• CPC Class Codes: G05B 2219/24032 Power on reset, powering up
• CPC Class Codes: G05B 2219/25289 Energy saving, brown out, standby, sleep, powerdown modus for microcomputer
• CPC Class Codes: G05B 2219/25458 Opto isolation, optical separation

Abstract

A power-up circuit is provided for a microprocessor based appliance control which includes a power source providing power between first and second conductors. A first circuit is connected across the conductors and a second circuit is electrically disconnected from one of the conductors and from the power source by a normally open switch. The second circuit includes a microprocessor control and the first circuit includes a relay coil for controlling the normally open switch. An optically coupled solid state relay couples the first and second circuits through a pair of light actuated silicon controlled rectifiers in the first circuit for energizing the relay coil and a pair of light emitting diodes in the second circuit for illuminating the light actuated silicon controlled rectifiers. A touch switch and related components are associated with the first circuit and are responsive to manual actuation of the touch switch to initiate energization of the relay coil independent of the light emitting diodes to effect closing of the normally open switch and connection of the second circuit to the power source. After this connection, the light emitting diodes will emit light to illuminate the silicon controlled rectifiers and maintain the relay coil in an energized posture until the cycle is terminated through the microprocessor control.

Claims

1. A power-up circuit for a microprocessor based appliance control, the combination comprising:

a power source providing power between first and second conductors;

a first circuit portion connected across said conductors;

a second circuit portion electrically disconnected from one of said conductors and from said power source by a normally open switch means and including a microprocessor control, said first circuit portion including means for controlling said normally open switch means;

means for operatively coupling said first and second circuit portions including light actuated means in said first circuit portion for energizing said means for controlling and further including light emitting means in said second circuit portion for illuminating said light actuated means;

means including a touch switch responsive to manual actuation for energizing said means for controlling independently of said light emitting means to effect initial closing of said normally open switch means and connection of said second circuit portion to said power source, said light emitting means being operable upon connection of said second circuit portion to said power source for emitting light to maintain said light actuated means operable for energizing said means for controlling; and

means connected to said microprocessor control for controlling operation of said light emitting means responsive to said microprocessor control.

2. A power-up circuit as defined in claim 1 wherein said means for controlling further includes a relay coil.

3. A power-up circuit as defined in claim 1 wherein said light actuated means includes at least one light actuated silicon connected rectifier operable for energizing said means for controlling.

4. A power-up circuit as defined in claim 3 wherein said light emitting means includes at least one light emitting diode operable for illuminating and energizing said light actuated silicon controlled rectifier to effect energization of said means for controlling.

5. A power-up circuit as defined in claim 1 wherein said means for operatively coupling includes an optically isolated solid state relay for effectively electrically isolating and operatively coupling said first and second circuit portions.

6. A power-up circuit as defined in claim 1 wherein said means including a touch switch further includes a semiconductor device for electrically energizing said means for controlling through said light actuated means.

7. A power-up circuit for a microprocessor based appliance control, the combination comprising:

a power source for providing power between first and second conductors;

a first circuit portion connected across said pair of conductors;

a second circuit portion electrically disconnected from one of said conductors and from said power source by a normally open switch and including a microprocessor control, said first circuit portion including a relay coil for controlling said normally open switch;

an optically coupled solid state relay for operatively coupling said first and second circuit portions including a pair of light actuated silicon controlled rectifiers in said first circuit portion for energizing said relay coil and a pair of light emitting diodes in said second circuit portion for illuminating said light actuated silicon controlled rectifiers;

means for initiating a cycle of operations including a touch switch assocated with said first circuit portion and responsive to manual actuation for energizing said relay coil independently of said light emitting diodes to effect initial closing of said normally open switch and connection of said second circuit portion to said power source, said light emitting diodes being operable upon connection of said second circuit portion to said power source for emitting light to maintain said light actuated silicon controlled rectifiers operable for energizing said relay coil; and

switching means connected to said microprocessor control for controlling operation of said light emitting diodes responsive to said microprocessor control.

8. A power-up circuit as defined in claim 7 wherein said means for initiating a cycle of operations includes a semiconductor triggering device operable for effecting said indepedent operation of said relay coil.

9. A power-up circuit as defined in claim 7 wherein said switching means includes a semiconductor device operable under control of said microprocessor control for conducting current to deenergize said light emitting diodes.

10. A power-up circuit as defined in claim 7 wherein said solid state relay is operable for effecting electrical isolation while maintaining an operative coupling of said first and second circuit portions through said light emitting means and said light actuating means.