We found this circuit in a 1987 documentation. It is a multi-tester with neon lamp and LEDs operating with both low continuous voltage and high alternating voltage.
This PLL circuit includes a small amplification stage. We found it in the December 1989 Radio...
Found in English documentation from the 1980s, this 3 transistors siren directly drives a small...
We found this circuit in a 1995 publication. It makes use of infrared LEDs of the type existing at...