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.
This circuit was found in a Popular Electronics documentation from the 90s. It is possible to switch...
This fuzz circuit is more elaborate with the previous ones, as it has a selection switch that...
The circuit presented is based on the National Semiconductor's LM3524, a component not common...