This circuit is based on the light comparison of two LDR sensors. We found it in a 90s Popular Electronics. The transistor must be according to the indicator or load being driven.
The 556 integrated circuit is a double 555. The heats of the components depend on the frequency and the...
This circuit was found in a 1966 American publication. The critical component is the tunnel diode. ...
This circuit is intended for the testing of junction FETs, providing several reading options...