We found this circuit in the November 1974 Radio Electronics magazine. The capacitors determine the output time, and it is normal to obtain 1 second for each uF used.
The sensor in this circuit is a BA315 diode. Other diodes can be experimented, but this is one...
This circuit tunes MW radios to apply the signal to a good audio amplifier. The circuit is from an...
This circuit can use both separate LEDs and a common cathode display when one segment indicates...