Outlet Relay Module

DISCLAIMER: In this project, you will be wiring a device that uses 120VAC. This is my first 120VAC project. I do not claim to be an expert with electricity. In fact, I claim just the opposite...I am an electicity novice. I do not know if anything I recommend here violates any codes or anything like that. Use this information at your own risk.

Over the past couple of years, I have started using what I call outlet/SSR modules to control my lighting. These modules consist of a Solid State Relay (SSR) connected to an electric outlet, and all this is stuffed into a plastic electrical box to make sure the 120V connections aren't exposed. These work very well for lighting. The SSRs I have are rated for 10 amps, well above anything I'll ever use, and the nice thing about SSRs is that they have no moving parts, so they are totally silent. Also, it can be triggered directly from a microcontroller like a PIC or Basic Stamp without needing any additional transistors or diodes, so it is really simple to use.

There are a couple of drawbacks to SSRs. For one thing, they are fairly expensive. For instance, the SSRs I bought at Futurlec go for $10. The other issue, or so I've been told, is that they're really geared towards resistive loads, such as lights, not inductive loads like motors. Because of this limitation, I decided to create a very similar module except that it uses a standard relay instead of an SSR. The big difference in constructing one of these vs. the SSR module is that, because the relay is so much smaller than the SSRs I used, I didn't need a double gang electrical box. It all fit in a single, standard box.

This how-to is broken up into 10 pages (including this one):

Parts list
Tools list
Construction part 1
Construction part 2
Construction part 3
Initial Testing
Construction part 4
Final Testing
Using the Module

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Page last modified 05/02/2009