Abstract: Inventory control devices and methods for controlling the inventory of a data storage system are disclosed. In one embodiment, the inventory control device comprises a sensor to sense a position of an access device of a data storage system, the access device having an open position and a closed position, a circuit communicatively coupled to the sensor to output a circuit state indicating if the access device was opened while the data storage system was shut down, and control logic communicatively coupled to the circuit to cause the data storage system to inventory one or more storage locations associated with the access device only if the circuit state indicates the access device was opened.

Abstract: A circuit for sensing the presence of an inductive load that is particularly applicable to sensing when a solenoid is being driven by a pulse width modulation (PWM) signal. The circuit includes a high side connected transistor having an output driving a load, with the transistor driven by a PWM signal. A circulating diode is coupled to the driving output of the transistor. The circuit further comprises an operational amplifier (op amp) circuit that is coupled to the circulating diode and operates as an inverting operational amplifier (op amp). The op amp circuit charges a first capacitor when the transistor releases driving an inductive load.

Abstract: A power supply load balancing apparatus comprises a voltage converter capable of accepting a plurality of supply voltages and converting a selected supply voltage selected from among the plurality of supply voltages to an output voltage, and a controlled rate switch. The controlled rate switch is coupled to the voltage converter and capable of selecting from among the plurality of supply voltages. The controlled rate switch applies switching among the plurality of supply voltages at different rates to unambiguously apply the selected supply voltage to the voltage converter.

Abstract: A circuit for sensing the presence of an inductive load that is particularly applicable to sensing when a solenoid is being driven by a pulse width modulation (PWM) signal. The circuit includes a high side connected transistor having an output driving a load, with the transistor driven by a PWM signal. A circulating diode is coupled to the driving output of the transistor. The circuit further comprises an operational amplifier (op amp) circuit that is coupled to the circulating diode and operates as an inverting operational amplifier (op amp). The op amp circuit charges a first capacitor when the transistor releases driving an inductive load.

Abstract: An electrical system for disabling incoming phone calls at selected times and routing calls during these times to a recorded message or an answering machine without ringing the phones in a specific area. This system also allows emergency calls to pass through and ring when normal incoming phone calls have been disabled. The times when calls are disabled may be selected by either pushing a specific button or programming the system through an alphanumeric keyboard.

Abstract: Method and device for reducing the time constant of a system having a conductor connected thereto by connecting an impedance between the conductor and a potential as the voltage on said conductor exceeds a preselected value.