In the figure we have a good rectangular signals generator with several frequency bands. The circuit is based on old logic but can be implemented with modern equivalents.
Using transistors and lamps, this simple circuit was found in Popular Electronics. The circuit can...
Using an operational amplifier, the figure shows how to convert the waveform to low frequency...
In the figure we have the way to increase the voltage of a 78xx by adding a zener diode. The...