This is page 7 of 10 of a how-to on how to build an outlet/relay module. The main project page is here.
Before we go any further, I would recommend testing what we've done so far to make sure all the solder connections are good. Here is how I tested mine.
I took my multimeter and put it in "continuity" mode. This means that when the 2 probes are placed in a circuit where there is very little resistance, the meter will beep. So, if you touch the 2 probes together, it will beep. If you put a piece of uninsulated wire between them, it will beep. If you touch them to a block of wood, it will not beep, as there is too much resistance.
Now, for the hookup. Attach one of the probes to the loose end of the 5-inch wire, possibly using something like an alligator clip. This will indirectly connect this probe to one pin on the relay.
Attach the other probe to the narrower blade on the power cord plug. If you were about to plug the power cord into the wall, the narrow blade is the one that would be on the right side. This blade is connected to the longer wire (the brown one, in my case) of the power cord. Since the brown wire is connected to another pin of the relay, when the relay is switched on, the circuit will close, causing the multimeter to beep.
Connect a power supply of the appropriate voltage based on your relay to the 2 pins of the terminal block. In my case, I used a 5V power supply, since the relay I'm using is a 5V relay. When you turn on the power supply, the relay should switch, and the meter should beep. If this didn't happen, you need to check your connections.
Click here for a 3 minute video that demonstrates how I tested the module. It is about 7MB.
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Page last modified 03/28/2009