remote control operated alaram circuit

1. REMOTE CONTROL APPLICATIONS
Department of Electrical and Electronics Engineering
K L University
Accredited by N.B.A and N.A.A.C “A” Grade
Green fields, Vaddeswaram, Guntur Dt, AP, Pin-522 5
ABSTRACT
REMOTE CONTROLAPPLICATIONS
IR circuit is called Infrared Circuit. Remote controls are very much popular now-a-days. It is
specially called cordless circuit. This circuit is very simple and low cost cordless remote control
circuit which is based on infrared rays. Figure 1 shows the transmitter circuit. The transmitter
produces infrared rays and that can be easily transmitted up to 4 meters with a special convex
lens and a twin LED arrangements. Figure 2 shows the receiver circuit. Op amp IC1-741
generates high frequency squire wave which provides the gate pulses for SCR1. IC1’s output
current flows through SRC1 and it is conducting current and enables the LED to emits infrared
rays. The output frequency of Op amp IC1 depends on the variable resistor VR1, which in turns
varies the output radiations of the LED. When IR rays fall on the photo-transistor T1 of the
receiver, then base of the photo-transistor’s base produces charge carriers at a rate depending on

2. the rate of arrival of incident radiations at the pn junction of the transistor. Then the resulting
emitter voltage is amplified by Op amp IC-2 . The amplified signal is rectified by D2. Finally the
amplified signal is to drive the relay.

3. PROJECTGUIDE:-
N.V.K.RAMESH