Found in Popular Electronics from the 1990s, this variable frequency circuit generates signals in the shortwave range. FETs admit equivalents.
This simple bridge circuit can be used for impedance or resistance measurement using a high...
This circuit can source up to 1,000 V from a 9 V battery. Output current is very low, some...
The figure shows how to change the frequency of a 5 V LED blinking. The capacitor can have other...