Tele-visage / Mustaqim Mustafa and Shah Rull Sulaiman

This circuit is combination between counter and opto coupler ICs, which can be used in any product, which used low voltage to light in the dark such as bell door and telephone. The low voltage from ring signal through bridge rectifier activates diode in opto coupler ICs. The pulses from opto coupler goes to SCR grounded, meanwhile the pulses signal goes to IC timer and generate loudspeaker to produce sound and in the same time turn on the SCR.. The lamp, which connected SCR. in series but in parallel with bridge rectifier, an output transform and IC timer, will turn the lamp on.