This simple source with zener regulation is ideal for experimental projects with operational amplifiers. Other voltages can be obtained by changing the zeners and the transformer.
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....