Found in a 90’s American documentation, this circuit indicates the frequency of input pulses up to 1 kHz. The circuit has a very explored configuration on this site.
Critical components of this project are the Geiger tube and the 300V battery. The battery can be...
Found in a 1967 Ferranti documentation, this regulator makes use of an operational amplifier of the...
Found in a Popular Electronics from the 90's, this circuit can generate frequencies according to the...