Power supply with increased dynamic range
AssigneeFairchild Camera and Instrument Corporation
InventorRobert S. Olla
Life of this patent
Estimating the term…
Abstract
A power supply circuit impresses a signal supplied by a pulse generator (28) at one frequency on an alternating current such as a standard AC signal at 115 volts RMS and 60 hertz by utilizing a single switching transistor (Q1) coupled between the pulse generator (28) and a current-directing element (14) which, in turn, is serially coupled between a source (10) of the alternating current and a load (18). The resultant bidirectional output voltage across the load (18) may be rectified and averaged to produce a substantially constant DC voltage whose level is regulatable by controlling the duty cycle of the pulse generator (28).
Claims17
A power supply circuit for converting an alternating current at an input frequency into an output signal at an output voltage/current level different from the input voltage/current level of the alternating current, a voltage/current source supplying the alternating current which alternately switches flow between a pair of current-flow directions opposite to each other, the circuit comprising:
- means responsive to a feedback signal for generating a first signal at a first frequency at least one order of magnitude greater than the input frequency;
- a switching transistor which alternately switches on and off at the first frequency in response to the first signal, the transistor having a pair of current-flow electrodes;
- means for directing the alternating current in a single current-flow direction through the current-flow electrodes when the transistor is on and for directing current flowing through the current-flow electrodes back to its original current-flow direction of the pair of current-flow directions, the means for directing substantially not directing current to the current-flow electrodes when the transistor is off, the first signal thereby being impressed on the alternating current to define a second signal;
- means, serially coupled between the voltage/current source and the means for directing, for rectifying the second signal and for averaging it with respect to time to produce the output signal therefrom;
- and
- feedback means responsive to the output signal for producing the feedback signal to provide feedback regulation of the output signal.
Dependencies are inferred from the claim text.