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.
This fully isolated control circuit provides an output signal by triggering a 130 mA relay when...
The capacitor used in this circuit can have values between 5 and 30 uF. The circuit is of old...
We found this circuit in an old Argentine publication. The transistor can be replaced by a more...