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.
This circuit was taken from the 1974 Ferranti transistor manual. Transistors are common types at...
This circuit is suggested by National Semiconductor and makes use of the negative regulator LM2990...
The transistors in the presented circuit can be the BC548 and the filter in front of the...