Abstract: A method for controlling the application of a voltage supply to an electrical load is disclosed. A characteristic of the voltage supply is determined. In response, the method causes disconnection of a control signal from a contactor. Disconnecting the control signal causes the contactor to disconnect the voltage supply from the electrical load.

Abstract: A voltage regulator includes a source port configured to be coupled to a power source and a load port configured to be coupled to a load. The voltage regulator also includes a constant current source circuit in electrical communication with the source port and the load port configured to regulate current flowing between the source port and the load port. Current flows in both a positive direction and a negative direction between the source port and the load port, and the constant current source circuit regulates the current that flows in the positive direction and the current that flows in the negative direction.

Abstract: An adverse condition detector that records historical data concerning the operation of the detector such that the detector can be interrogated by a technician. The microprocessor of the adverse condition detector monitors for alarm conditions and other important information related to the operation of the detector. Upon identifying an important characteristic of the detector operation, the microprocessor time stamps the information and stores the information within memory of the microprocessor. The detector includes an interface pad that is accessible from the exterior of the detector such that a technician can access the interface pad without removing the detector housing.

Abstract: An alarm system for signalling when a door of a refrigeration unit compartment is not fully closed comprises an alarm condition sensing system having a door sealing gasket magnet and a magnetically actuated switch. The gasket magnet produces an elongated narrow magnetic field for coupling the unit and the door in sealing relationship when the door is fully closed. The switch senses the magnetic field when the door is closed even though the magnet position may be anywhere in a band of possible positions. An alarm system signals when a door of a refrigeration unit compartment is not fully closed. The alarm assembly comprises a housing wall section, a vibratable alarm member, and mounting structure for connecting the alarm member to the housing wall section so that the housing wall section is driven by the member and vibrates relative to the housing when the member vibrates at an operating frequency. A plainly audible alarm is produced when a door ajar condition is sensed.