Suggested by a 90s EDN, this circuit supports almost any LED as a source and a phototransistor as a detector. The circuit operates with a PLL 567 at a frequency of around 40 kHz.
Pressing and releasing S1 remains one of the neon lamps. Which one will be, it is not possible to...
This circuit, which appears on our website in different versions, uses an integrated VU which is...
This VCA was found in the July 1988 issue of Radio Electronics magazine. It uses an OTA op amp and...