RF or even switching transistors like the 2N2222 can be used in this circuit. The capacitors are ceramic and the frequency is determined by the crystal.
This circuit triggers on a relay after a time delay adjusted by P1. The range of times achieved by...
This fish flame circuit was found in a 1971 magazine. The circuit can still be mounted with BC558...
September 2017 - Texas Instruments PCM186x and PCM186x-Q1 Audio ADCs can be found at Mouser...