Abstract: The power supply of the present invention is designed to operate over a wide range of both ac and DC input voltages and frequencies from 0-400 Hz. The power supply also provides two DC low voltage outputs, one for devices that do not require a high degree of regulation and one for devices that do require a high degree of regulation. The power supply also includes a power-up inrush clamp to limit high start up currents to approximately two times the nominal switching current. The primary switching transistor of the power supply is controlled by a dynamic feedback circuit which works interactively to increases the switching speed of the primary switching transistor.

Abstract: The invention provides an oscillatory suppression circuit (54) for use in a photosensor loop circuit (10) employing a phototransistor (14). The oscillation suppression circuit (54) prevents oscillation in the photosensor loop circuit (10) caused by detected unmodulated high frequency light. The oscillatory suppression circuit (54) includes a resistor (58) and a capacitor (62) connected in series, and also connected in parallel with a base resistor (38) of a feedback transistor (26). The oscillatory suppression circuit (54) adds a small amount of phase advance to a feedback circuit (50). This small phase advance counteracts any additional negative phase shift produced when intense light pluses are detected by the phototransistor (14) and amplified by the high gain of the feedback circuit (50).