This polarity inverter circuit for voltages down to about -12 V was found in the December 1992 issue of Radio Electronics magazine. The current is a few mA.
This FET voltmeter is from an old 1974 amateur radio publication. The circuit can use MPF102 or...
This indicator was found in a 1974 publication, but it can be fitted with the BC548 transistor or...
This circuit was found in the comparator's own documentation, serving others in the same series. The...