Using the integrated circuit 723 we found this power supply in an article in the magazine Radio Electronics from August 1971. The transistor may be a BD136 equipped with a heat sink.
This circuit is a driver for R-2R network of AD converters. We found it in manufacturer...
This circuit was found in an American publication from the 60's. The transistor is made of...
This circuit produces an audio tone on the speaker or magnetic capsule. Rx must be such that added...