LED flasher (CB22143E)

The transistors in this circuit can be the BC548. Capacitors determine the frequency and can be changed. The supply voltage can also be changed.

Fast Half Wave Rectifier (CB15884E)
The circuit shown is based on the LM101A; diodes can be replaced with equivalents. Resistor R1...
Twilight Switch (CB12480E)
With the disappearance of the light falling on the LDR, the relay closes its contacts by...
Timeout Compator (CB5078E)
We find this circuit in an American 1980s documentation. Modern equivalent integrated circuits can be...