Abstract: The present invention is a battery transfer circuit connected to a load, a power supply for powering the load with at least a minimum supply voltage during normal operating conditions, and a source of battery voltage for powering the load during a power fail condition when the power supply is unable to power said load at the minimum supply voltage. The battery transfer circuit comprises a first circuit for applying at least the minimum supply voltage to the load during normal operating conditions and a second circuit for charging the battery to an optimal voltage greater than the minimum supply voltage and for down-regulating the optimal charge voltage to a predetermined voltage and for applying the predetermined voltage to the load during the power fail condition, wherein the predetermined voltage is less than the minimum supply voltage.

Abstract: A circuit for controlling current flow though an LED backlight network, comprising a PWM circuit for receiving an input DC voltage (Vsource) and in response generating a chopped output voltage (Vsw), a filter for smoothing the output voltage (Vsw) resulting in a DC output voltage (Vout) for application to a first terminal of the LED backlight network. A resistance (Rcp) is connected between ground and a second terminal of the LED backlight network so as to create a node voltage (Vref) connected to a feedback input of the PWM circuit. In operation, the PWM circuit maintains a constant controlled current through the LED backlight network by regulating Vout in accordance with the node voltage (Vref).

Abstract: The present invention is a switching power supply having efficient light load regulation at high input voltage. The power supply comprises a pulse-width modulator integrated circuit along with two separate voltage buses. A transformer is connected to the first voltage bus via a first primary winding and is connected to the second voltage bus via a second primary winding both primary windings have a predetermined number of turns proportional to voltages supplied by the two voltage buses. The power supply further comprises a pair of switches connected to the two primary windings and driven by the integrated circuit.

Abstract: The present invention is a battery transfer circuit connected to a load, a power supply for powering the load with at least a minimum supply voltage during normal operating conditions, and a source of battery voltage for powering the load during a power fail condition when the power supply is unable to power said load at the minimum supply voltage. The battery transfer circuit comprises a first circuit for applying at least the minimum supply voltage to the load during normal operating conditions and a second circuit for charging the battery to an optimal voltage greater than the minimum supply voltage and for down-regulating the optimal charge voltage to a predetermined voltage and for applying the predetermined voltage to the load during the power fail condition, wherein the predetermined voltage is less than the minimum supply voltage.

Abstract: The present invention is a switching power supply having efficient light load regulation at high input voltage. The power supply comprises a pulse-width modulator integrate circuit along with two separate voltage buses. A transformer is connected to the first voltage bus via a first primary winding and is connected to the second voltage bus via a second primary winding both primary windings have a predetermined number of turns proportional to voltage supplied by the two voltage buses. The power supply further comprises a pair of switches connected to the two primary windings and driven by the integrated circuit.

Abstract: A wrap-around auxiliary keyboard having (1) housing, (2) keys positioned in the housing and (3) circuitry means in the housing. The housing has a base and at least one extension extending from the base. The base and extension(s) are shaped and positioned with respect to each other so as to be able to wrap-around a primary keyboard.

Abstract: Any of a variety of trim pieces or components for buildings, the components having decoration according to a system providing for use of a wide variety of specific decorative patterns. The system provides for attachment to a trim or trim piece of separate means providing a decorative visual contrast with the trim piece itself.