This Vox or sound activated relay was found in an American documentation from 1975. Equivalent transistors can be used, and the SCR can be a TIC106. The relay is according to the supply voltage.
This circuit is from 2001 documentation and consists of a small FM transmitter with two inputs, one...
This amplifier, of excellent quality, provides a power of 40 W IHF, or 22 W RMS, in a load of 8...
The input of this regulator can be between 7 and 12 V and the output is 5 V. The circuit is from...