Homemade AC light dimmer

[Soundguy]

in my shop I have 2 things that may satisfy what the OP wants to do.

1, is a metal quad outlet box with cover with a dual outlet on one side, and a hd dimmer int he other.. push on, then turn. ( is a triac based drimemr.. not resistive ).. is rated for 600w inc load.

I have used it on lamps, and for limited us on a non variable drill one time..


the next unit is a router speed control.. i didn't build it.. bought it years ago. finally found it months ago.. it's rated for something like 15a


soundguy

 

[Brad_Blazer]

I was thinking about the router speed controller too. $20 at HF.
Router Speed Control

Here's a discussion starting at post #3
Tis the season for lighting gadgets - b-roll.net FORUM

 

[Redneck in training]

HE STATED he wanted it for a 3 prong plug.

Those were just examples what is available. If he makes his own then the white and green wire goes through and the dimmer is connected in series in the black wire.

 

[joshuabardwell]

Here few ready made:
Amazon.com: Westek 6089B 500W Full Range Foot Control Dimmer, Black: Home Improvement

500W DIMMER | AllElectronics.com

http://www.discountdimmers.com/index.php?main_page=index&cPath=1_27_130

I'm familiar with those, but none of them are three-prong. I intend to use this for temporary outdoor lighting. I will have a bunch of "Chinese Lantern" style lamps that will be on an extension cord/cords. The lamps themselves are two-prong, but the extension cords are three-prong, and it seems like a good idea to keep the grounding as far through the circuit as possible. Also, the ones I've found are only 300W max, while I can easily get 600W with a in-wall dimmer.

Before I learned of the router speed control, the cheapest 3-prong dimmer I could find was $50. The speed controller is a really tempting option, but I may end up rolling my own anyway, because it will still be marginally cheaper, and I like making things.

 

[Redneck in training]

My guess is that the speed control is more expensive due to inductive load that might generate voltage spikes during commutation. It has to be made from hardened components.
Make you own. Take two gang metal box, put 600 or 1000W dimmer in one and the two outlets in the other gang. One outlet dimmed and the other 110V. Or both dimmed. Toggle or push and rotate dimmers fit in the metal outlet/switch combo cover for the box.

 

[Soundguy]

that's what I did...

 

[joshuabardwell]

Thanks for the input, guys. I ended up making one out of about $25 in parts. The extension cord was the most expensive part. I couldn't find much of a cheap one with three prongs. If I had gone two-prong, the whole thing would have come in under $10. With tax, I about broke even with the router speed controller from Harbor Freight. The Harbor Freight speed controller handles up to 1000 watts, while my dimmer only handles 600 watts. The speed controller also has an on/off switch as well as a dimmer. I figured that after shipping, I would still come out ahead, but it turns out there's a Harbor Freight in Knoxville, so I could have just picked one up. Either way, it's not too big a deal. I kind of like the "industrial" look of my home-made dimmer, compared to the professional look of the dimmer.

While I was building it, I tested out the wiring with a multimeter. The multimeter showed no continuity on the hot wire! I decided to just plug in a light bulb and see if it worked, and it didn't. So I pulled everything apart and started testing it all. Well, it turns out that AC light dimmers aren't simple rheostats. They have a diode in there that chops off the tops of the AC signal. So they don't show any continuity with a simple multimeter even when the switch is open. In other words, everything was wired up fine. So why didn't the light turn on when I plugged it in? Because the light bulb was burned out! Duh.

 

[Soundguy]

. Well, it turns out that AC light dimmers aren't simple rheostats. They have a diode in there that chops off the tops of the AC signal. .

I'll bet if you look closer you actually find a triac....

soundguy