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.
In the figure we have a circuit suggested by National Semiconductor, using an operational...
Tone controls for audio applications can also be considered filters that must attenuate certain...
This circuit was found in an Argentine publication from 1973. It uses a common AM coil (50 + 50...