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Relay is not switching devices On/Off

PostPosted: Sat Aug 06, 2016 3:00 pm
by Bains
Hi,

I'm new to IOT stuff. I recently started working on a simple project to switch on/off a lamp using 8266 (ESP-12e) and relay. I'm able to successfully create a web server and control led connected to ESP-12e. When I connect relay to the same pin, instead of led, I can see small led on relay board responding (going on/off) to signal from pin. But when I connect a lamp with relay, then lamp doesn't work at all. Seems like circuit is not complete. I tried 2 different relays and also tried (NC-COM) as well as (NO-COM) combinations, but results were same. It would be great if someone can suggest what's going wrong here. Please find pictures of breadboard attached.

Re: Relay is not switching devices On/Off

PostPosted: Sun Aug 07, 2016 7:45 am
by martinayotte
According to picture, this relay board doesn't seem to have a transistor driving the relay.
Am I right ? (maybe you should provide a picture from top and bottom)
If there is no transistor present, the ESP GPIO cannot provide enough current to drive the coil.
In such case, you need to add one.

Re: Relay is not switching devices On/Off

PostPosted: Sun Aug 07, 2016 8:57 pm
by Bains
Thanks for your reply. I suppose this relay should have transistor as I heard that it can be used as it is. Sorry, I am from programming background so can't confirm. But I do hear a slight "TICK" sound when I toggle the pin status connected to the relay. Please find the pictures of the relays that I have tried attached. Thanks again for your help.