This circuit is from 1973 documentation. The transformer has 500 mA of current and the transistor can be the TIP32 mounted on a heat radiator.
We found this simple frequency meter for low frequencies in an English publication from 1978. The...
We found this circuit in documentation from the 90s. The circuit has a latch. The power supply must...
The original purpose of this 1963’ circuit from a magazine is to replace the mechanical vibrators used...