A solid-state high-voltage regulation circuit for devices such as televis receivers which incorporate a flyback transformer. Voltage changes across the transformer secondary winding are compared to a stable reference, and any difference is amplified and applied to control the flow of current to the transformer primary coil. The output voltage is thus maintained essentially constant.
A high-voltage stabilizing circuit for stabilizing high voltages such as those generated by the fly-back transformer of a television. The stabilizer includes a common-emitter type PNP transistor and an inverse current-absorbing capacitor with a small capacitance in order to provide a high-speed response. The collector of the transistor is connected with the primary coil of the fly-back transformer and the capacitor. The emitter of the transistor is connected with a power source. With this arrangement, even though parabolic wave voltages are generated at the capacitor due to the small capacitance, the PNP transistor hardly cuts off at all and can therefore supply adequate current to the fly-back transformer.
A control circuit for a solid state inverter includes a sensor responsive to instantaneous transformer flux which provides an output signal to control the switching times of a pair of solid state switching devices in the inverter to maintain a constant level of peak flux for each half cycle of operation of the inverter. An additional current sensor provides for peak current limiting to prevent overcurrent in the case of short circuit output conditions.
In a current-density controlled source of high-voltage current fed from a low-voltage current source and supplying a high-voltage direct current to two output terminals, an error voltage resulting from the comparison of a constant reference voltage and the voltage appearing at the terminals of a resistor through which flows a current proportional to the current to be controlled acts on the amplitude of an alternative current signal produced by an oscillator, the amplitude variations of the signal produced by said oscillator causing the amplitude high voltage current supplied to said output terminals to vary.
A laser power supply includes a dc to dc converter which feeds a multiplier-rectifier circuit to provide a high dc voltage output. The converter includes a power transistor which is subject to a control of its on time to provide constant current regulation. A smooth regulation is provided by a proper timing of the turn off signal to the power transistor by sampling the emitter signal of a transistor which is included in a synthesized thyristor, the thyristor being operable to hog base current from the power transistor. The converter is coupled to the output multiplier-rectifier by a transformer which has a feedback winding connected in series with the base of the power transistor.
Disclosed is a system of paralleled switching power supplies designed and controlled to have substantially identical output voltages and impedances so as to share the load equally. The output voltage of each supply is controlled to decrease linearly with increased output current, and the individual power supplies and their control circuits are designed and controlled to behave as identically as possible under the expected service conditions such that, under any given set of conditions, the output voltages and impedances of the several individual power supplies can be expected to be substantially identical and therefore they can be expected to share the load substantially equally. Provisions are made to make the control of the individual power supplies substantially independent of variations in the resistance of the power cables connecting them to the common load.
