This simple metronome, from 1985 documentation uses only transistors and has two settings. For voltages above 6 V, up to 12 V, replace the BC557 with a BD136.
The configuration shown can be applied to modern operational amplifierso with common power...
This circuit appeared in Radio Elecronics magazine in 1968. The operating circuit is a...
The circuit shown is from a September 1973 Radio Electronics. It reduces the full scale of a...