Abstract: A display cabinet for storing and displaying merchandise for sale to consumers is provided with one or more doors, each door being locked by a locking mechanism that can be released by a signal from a remotely located, hand-held RF transmitter operated by a store clerk or cashier. Visual and audible alarms are provided for alerting store personnel to forcible entry into the cabinet and for warning store personnel when the cabinet doors have been open for a time period in excess of a predetermined time period.

Abstract: A circuit for testing a computer battery without removing it from the computer includes a plurality of serially connected resistors, and a transistor connected to saturate. The voltages at the junctions of the transistors is sensed by a logic device such as a buffer, for application to the data bus of the computer. The transistor may be controlled from the computer via a latch. The resistors have values to produce voltages at two sensed resistor junctions such that the corresponding logic levels applied to the computer are the same, at a first level, when the battery voltage is acceptable, are the same at another logic level when the battery voltage is unacceptable, and are different when the battery voltage is between acceptable and unacceptable voltage values.