The time of this timer depends on C1. The circuit was found in the July 1994 Electronics Now magazine. The supply voltage depends on the relay and can go up to 12 V.
This 1970s RCA circuit can be triggered by light or dark, depending on how the LDR is connected....
Found in a 1980s American documentation, this crystal-controlled oscillator generates 100 MHz...
This flasher circuit consists of an astable multivibrator with the frequencies given by the...