This traditional configuration with the 555 was obtained in an 80s Hands-On Electronics. The relay is of the sensitive type according to the supply voltage.
We found this circuit in a 1990s documentation. The circuit uses components from the era providing...
This 1968 circuit makes use of MOSFETs of the time. The circuit can be mounted based on modern...
Suggested to power the previous circuit, this power supply was found in the December 1990 issue of...