Can I use USB to power a Relay?? Answered
I have purchased a simple 4 channel relay (http://www.fort777.co.za/index.php?main_page=product_info&cPath=800_801_946&products_id=10357&zenid=fvokss9s9ucgakrrn9ged441hs1oushq) My Aim is to use the USB port on my TV to control the relay. The intention is to have it switch on a lamp when the TV is powered up. I have run into an issue and being a bit of an electronics novice I am not sure what to do. The Relay kit as both a 12v input (I assume that is to actually power the relay coil) as well as a connector that has pins for Ground, 5v and Signal for each relay (S1 - S4). If I attach the red wire from USB (5v) to S1, and the ground from the USB Cable (Black) to ground, the indicator LED flickers and then dies. at no point does the relay click, and the light seems unaffected whether the 12v power is connected or not. I feel I might be missing something simple, but as an utter novice in this area I am not sure. Any help.