I have a pretty basic question about how to wire and use a simple power supply.
I have a simple 5v breadboard power supply (MB102). I want to use it to control a 5v relay. I want the relay to switch when power is turned on or off on the power supply.
I can get my project tow work if I wire it through an arduino board.
Arduino 5v to relay +
arduino ground to relay -
Arduino 5v to relay "S".
With this setup the relay switches when power to the arduino is turned on and off. (It also switches if I plug and unplug the "S"line.
For some reason I cannot recreate this simple setup with my power supply. The power supply is set to deliver 5V. I wire as follows:
Power supply 5v to relay +
Power supply GND to relay -
Power supply 5v to relay "S"
When I plug this in I do not here the "click" of the relay switching. I also note the led on the power supply turns on but is dimmer than usual. I measured the voltage the power supply generates when connected to my circuit and it has dropped from 5v to under 3.
I figure the power supply is a dud or more likely I am missing some pretty fundamental knowledge of how electricity works in these projects.
Power supply: http://www.ebay.ca/itm/180936853408?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT