Robertshaw Controls Company

Ranco Inc. of Delaware

Other

Ranco Incorporated of Delware

Leonard W Jenski

Robert J Alvord

Bay E Estes

Daniel Zuzuly

Kevin G Nowobilski

Raymond Bambule

Guy Mereness

A system for detecting the miswiring of an electrical appliance that includes a microprocessor having first and second input connections to sample signals on two different electrical power lines. The microprocessor further includes a third input connection for a neutral line. In an embodiment of the invention, there is at least one switch through which electrical power can flow into a load. The at least one switch is controlled by the microprocessor. In a particular embodiment, the microprocessor is configured to compare the signals sampled at the first and second input connections to determine whether the electrical appliance has been wired correctly.

System and method for detecting miswiring of an electrical appliance

A defrost heater relay control circuit having reduced power consumption during a de-energized mode of operation is provided. The relay drive circuit utilizes a series connected capacitor to introduce a phase shift in the AC current waveform such that the amount of real power dissipated in the circuit during periods when the defrost heater control relay is de-energized is greatly reduced. This effectively shorts out the relay drive voltage without generating heat due to real power dissipation through the switched circuitry that disables the relay.

Adaptive defrost control circuit with relay power saving feature

A driver circuit for a latching type valve is provided which utilizes an electronic switch assembly to provide the dual polarity necessary to actuate the latching type valve to both its open and closed states. The driver circuitry includes a microprocessor and a slope detector circuit for monitoring the coil current used to energize the valve solenoid to determine when the valve armature has moved to its fully actuated position. The driver circuit preferably utilizes power MOSFET devices in the switch assembly configured into an H-bridge to drive the solenoid coil. Advantageously, the user of power MOSFET devices eliminates the necessity for a current sense resistor in the control circuitry, thereby decreasing power dissipation and increasing efficiency of the drive circuit, thereby prolonging the battery life used to drive the valve. A pulse of fixed duration may be utilized to transition the valve to an OFF position, or a second slope detector may be implemented to control the transition to the OFF position in like manner. Monitoring of the actual time required to actuate the valve may be utilized to signal low battery voltage or a failed valve, if desired.

Driver circuitry for latching type valve and the like

An electromechanical relay drive system which prolongs relay life by ensuring operation of the relay in a manner to make and break contact between the contact electrodes at a zero crossing point of the switched waveform. Relay aging and environmental variations are dynamically compensated upon each actuation of the electromechanical relay to ensure proper timing of the energization and de-energization of the relay to ensure switching at the zero crossing point. Additionally, the drive system described compensates for variations in the actual contact operation during actuation for the positive and negative half cycle of the switched waveform. Furthermore, the system of the instant invention alternately energizes and de-energizes the electromechanical relay during the positive and negative half cycles of the switched waveform to prevent metal deposition from one contact electrode to the other. This system calculates the appropriate delays on a dynamic historical perspective by sensing slope changes of the coil voltage and current.

Zero cross relay actuation method and system implementing same

A method and apparatus for operating and executing a self-test routine of an LED display device adapted for assembly into home appliance. The device is comprised of a plurality of LED elements, a control processor, a switch assembly, and a signaling element. The self-test routine comprises disposing the switch assembly in a predetermined pattern for detecting switch operability and initiating a program in the processor for self-testing of illumination of the LED elements. The elements are monitored during the self-test routine for communicating a minimum current level preselected as identifying proper illumination. Failure of the self-test routine to properly detect minimum current levels precludes a proper response from the signaling element within a predetermined time limit, thereby causing the display device to be identified as an unacceptable device.

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Roselle, IL, United States of America

Leonard W Jenski