Signals of up to a few tens of kilohertz can be generated by this circuit found in a European publication from the 1980s. Transistors admit equivalents and the unijunction can be 2N2646.
This bistable touch circuit using CMOS technology controls a relay. The supply voltage must be...
This project is from the book Science Fair Projects by Newton C. Braga. In it we have a relay that...
This circuit was obtained in an old documentation, but it is still current by the used components....