This circuit was found in the Electronics Experimenter Handbook from 1991. The circuit controls a simple relay for the purpose of turning circuits on or off or switching audio channels.
This circuit, bridge type, was found in American documentation from the 60's. The transistor is...
This inverter is critical for transformers and can use modern equivalent transistors like MJ2955 on...
This low-current power supply was obtained in Japanese documentation from 1968. The currents are...