The transistors of this circuit found in a 1965 magazine can be the BC558 and the sensitive 12 V x 50 mA relay. The other components are common.
Relays up to 100 mA can be driven by the 555 with the recommended circuit. The circuit is from an...
This type of circuit and with this integrated circuit appears several times on this website. The...
This circuit was obtained from a 1985 Electronic Desing. The circuit uses a Darlington which may be...