We found this circuit in the 1964 RCA transistors manual. The transistors used are uncommon today, but they can be used equivalent. The circuit controls the operation of a heating element.
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...