This small regulated power supply was found in a 1963 General Electric documentation. The special zener diode transistor can be replaced with an equivalent discrete configuration.
Found in an Electronic Design from the 90's, this circuit uses common components. The circuit is...
When the sensor receives light, the relay closes its contacts and remains so even after the light...
This circuit produces pulses of 90 V at intervals that can reach 5 minutes. The circuit is from a...