Abstract: A current monitoring scheme operates in an indirect fashion to estimate the current output of a circuit from a measured voltage output. Voltage data is processed in accord with state variable theory to derive a current estimate without direct sensing of the current.

Abstract: A current controlled switching type voltage regulator achieves voltage regulation by controlling an average current flow through the switching device. This current is sensed and transformed into a signal frequency. The signal frequency is counted to determine its average value and this count is compared to a variable current reference count which is continuously adjusted in response to an output voltage monitor which includes circuitry to generate an error count responsive to the deviation of the voltage output from a desired regulated value. In order to counteract instability problems inherent in current controlled switching type voltage regulators the transducer converting current into a signal frequency has a threshold characteristic to insure a definite fixed signal frequency at very low currents.

Abstract: A power supply system having a plurality of individual power supplies utilizes a master control to periodically compensate for errors in individual power supplies. The master control is periodically coupled to individual power supplies by multiplexing means to provide compensation signals to counter drifts and errors due to varying circuit parameters therein.