Found in a 90s Popular Electronics, this circuit uses a simple 9 V source. The power can be used from the circuit with which it works.
We found this circuit in a publication from the 1970s. It produces intermittent clicks on a...
We found this circuit in a Philips documentation from 1969. It makes use of transistors of the...
This circuit was found in a 1999 English magazine, but can be easily assembled with BC548...