This 18 V x 300 mA power supply was found in a 1969 documentation. The integrated circuit is difficult to obtain today.
We found this circuit in a technical documentation from the 70s. It can be implemented with more...
We found this shield circuit in a 1991 technical documentation. The phototransistor can be...
This circuit was obtained from a Radio Electronics from October 1963. The 4 transistors must be...