Remote control of home appliance circuit malfunctioning

Thread Starter

Joined Mar 12, 2014
Dear sir
I made Remote control of home appliance circuit . circuit is attached. I am facing problem that relay is tripping after few minutes automatically. I have covered TSOP1738 by small paper so that it should not be disturbed by nearby IR rays. I connected 220V, 40W bulb with Common point and NC terminal of relay. My relay is 6V dc has coil resistance of 103 Ohm. i am using 7805 regulator for 5V dc supply for this circuit. My bulb is tripping ON and OFF automatically after every few minutes. I am unable to understand why this happening?

Please help me to fix this problem as you are known to best in electronic circuit trouble shootings.


Image url is given below



Joined Oct 2, 2009
I moved your post to its own new thread. Hijacking someone else's thread is frowned upon.

Also it is not a good idea to use your email address as a screen name or to post your email address anywhere on the forum. It will invite a lot of spam.


Joined Sep 17, 2013
Your circuit is probably being triggered randomly by power-line noise. It is missing the recommended power line decoupling capacitor (4.7uF or greater) on pin 2 of the TSOP1738. I suspect that the schematic has an error and perhaps C1 +ve terminal should be connected to pin 2 rather than to pin 3?