This 1965 circuit uses a Philips 4068 tube to measure extremely small charges. The circuit has as indicator a micro ammeter and the transistors are of the time.
The circuits shown below consist of diode protections against accidental polarity reversal in the supply...
We found this circuit in the November 1994 issue of Electronics Now magazine. It doubles the...
The circuit presented is a simple MW tuner that can be plugged into the input of any audio...