This circuit was found in a 1980s documentation. It shows how to obtain a bistable with the 555 by directly driving two indicator LEDs.
The purpose of this circuit is to trigger an oscillator with the light of dawn. The tone of the...
This two-input limit detector was found in an American 1980s documentation. The circuit can be...
This circuit was obtained from a 1970s RCA. The circuit uses LDRs as sensors. The resistors depend on the...