This is one of the first radios with an integrated circuit. The circuit is from a Radio Electronics from November 1969. The circuit is powered by a 9 V battery.
This regulator can use BD'136 as the main transistor and as a reference next to a BC548 zener. The...
In the 110 V network, capacitors of 200 V or more and in the 220 V network, capacitors of 400 V or...
The circuit shown timing the drive of a motor using an optical coupler. The diode bridge can be...