This circuit can be used with 5 to 15 V sources and the zener diode must be chosen according to the trip voltage of the protector. The circuit blows the fuse when the voltage exceeds the zener value.
This high-power transistor amplifier was found in a 1995 documentation. The source is given in the...
In this circuit of a 1970s publication, data from the coil to oscillate at the desired frequency...
This circuit was published in an English magazine from 1980. The magazine no longer exists, but...