This 4-transistor amplifier can work from 4.5 or 6 V power supplies. We found it in a Mullard transistors manual from 1960. The transistors are from the time.
In the 110 V network, capacitors of 200 V or more and in the 220 V network, capacitors of 400 V or...
This circuit makes use of older operational amplifiers, but can be designed on the basis of modern...
This 12 V incandescent lamp switch with time delay can be found in old documentation. The SCR can...