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.
Figure 1 shows a hal-wave voltage doubler operating with the Power-supply voltage. Output current...
In the figure we have a circuit that allows us to obtain a variable voltage of approximately 0.5 to 25 V...
This circuit was obtained from a Linear Technology manual from the 1990s. The components may have...