Silent X10 mod (cheap SSR)

posted Dec 19th 2007 10:11pm by Will O'Brien
filed under: home hacks, misc hacks

I’m feeling a bit retro for the holidays, so here’s another classic: If you’ve got a non-dimming X10 switch, you’ve experienced the incredibly loud, obnoxious sound that it makes when you switch it on or off. (Mine’s in my stairwell) There’s a simple mod to silence the thing: remove the ~~triac~~ relay and replace it with a solid state relay. SSRs are a bit expensive, running at least $10 each last time I checked. [Willis Dair] realized that he could build his own, inexpensive SSR with an optoisolator and an alternistor(AKA Triac). The resulting circuit runs about $3 in parts.

Read

Comments [20]

Reader Comments

shoudlent it say remove the relay and replace it with a SSR?

Posted at 11:27 pm on Dec 19th, 2007 by Chupa

i guess the article is wrong. a triac is a solid state device (usually in a TO-220 package). It doesn’t make sense that that would be the cause of noise.

Posted at 11:31 pm on Dec 19th, 2007 by Chupa

Well the article says: “The original triac is removed and replaced with a solid-state relay.” which doesn’t make sense.

Posted at 2:24 am on Dec 20th, 2007 by Chupa

While we’re on it, shouldn’t the triac have a snubber across it, particularly if it is to be driving any kind of reactive load?

Posted at 4:40 am on Dec 20th, 2007 by chic

It’s important to remember that the mechanical relays in these switches are designed to handle high load items, which an electronic relay often can’t handle. It’s what allows the $50 switch to power motors, and heavy loads like 600V of incandescent lights, or a water heater. Replacing it could jeopardize the relative safety of the mechanical relay. The noise of the relay moving might be annoying but it’s providing a safety feature

Posted at 1:02 pm on Dec 20th, 2007 by Boyd

Not sure what you mean by a load of 600v? (particularly on a 115v circuit)

Posted at 1:23 pm on Dec 20th, 2007 by Wolf

byod probably meant 600W or incandescent lights, not 600v.

Posted at 1:32 pm on Dec 20th, 2007 by Admiral Michael

I suspect he meant 600 watts.

Posted at 1:36 pm on Dec 20th, 2007 by Orv

My bad. 600W. Just wanted to point out that relays serve a purpose.

Posted at 1:53 pm on Dec 20th, 2007 by Boyd

on the safety side, the worst that can happen is either it melts and shorts and blows the fuse, or it melts and stays open circuit. Either way no humans harmed…

Posted at 3:58 pm on Dec 20th, 2007 by O Mattos

it’s only no humans harmed assuming the other safety devices work correctly.

Posted at 5:14 pm on Dec 20th, 2007 by bobby

what kind of light would a normal household have thats 600w? I have a shop halogen light thats 500w. I couldn’t imagine a single light in a house with a normal plug requiring 600w.

As far as safety is concerned a solid state relay is a lot more safe in my opinion, given its rated to handle it load obviously. The spark a mechanical relay causes could lead to more problems than a SSR. Further more after extended use of a mech relay the contacts start to deteriorate(like welding). A SSR is only unsafe if not used properly, just like everything else in the world.

Posted at 6:27 pm on Dec 20th, 2007 by Chupa

“13. what kind of light would a normal household have thats 600w? i have a shop halogen light thats 500w. i couldn’t imagine a single light in a house with a normal plug requiring 600w.”

e.g. Multiple recessed lighting like kitchens and living rooms have a cumulative load. Exterior house lighting like spot lights, two on each unit 2 to 4 units adds up.

It’s the same for dimmers. If you want to dim 6 recessed fixtures that have 100W bulbs you would need a 600W dimmer.

Posted at 6:32 pm on Dec 20th, 2007 by Boyd

I agree with boyd – those stylish indoor recessed lights or mini-spotlights for paintings etc. can be 50w each, and with 20 of them around a room you could easily end up with 1kW of lighting.

Posted at 6:37 pm on Dec 20th, 2007 by O Mattos

I’d hope that if you’re messing with home electronics, and hacking them, no less, that you’d know how to calculate total load and choose the appropriate SSD. You could also put a pair of SSD switches in to get the load needed if one wasn’t enough.

Posted at 7:45 pm on Dec 20th, 2007 by the_fozz

@14,15

the X10 modules are for outlets. I dont play with x10 at all so maybe they make some for hardwiring, but I dont know. My questions is what kind of light with a standard plug on it would require 600w, as the article shows how to modify a x10 module for a standard electrical outlet.

Posted at 10:57 pm on Dec 20th, 2007 by Chupa

Solemn article. It make me lost in thoughts.

Posted at 3:43 am on Dec 21st, 2007 by Lucas

He’s using a 15 amp TRIAC, with fairly large heat sink. If something fails, it’s not going to be because he plugged in 700W of anything. He’s even using what Teccor calls a “snubberless” triac, which means it deals pretty well with reactive loads. He’s also using a zero-crossing-detecting optoisolator, i.e. what he’s built is _identical_ to a commercial SSR — just not potted in lots of epoxy.

Furthermore, unlike conventional relays, SSRs won’t fail after N switchings (due to mechanical wear and that it arcs inside the relay every single time you switch with a load). It’s pretty clear to me that the X10 guys used conventional relays because they cost 1/10th as much (and 1/3rd as much as the home-built SSR here), nothing more.

Posted at 11:13 am on Dec 21st, 2007 by rj

The (outdated) article discuss the multiple types of switches X10 makes including the wall switch, which use the same electronics. I have 480 W of lighting on a single switch in my living room. It’s normal in a lot of houses to have a high load on a single switch. It’s not just a plug-in module they have all sorts of hard wired units.

The updated version of the website that started the blog states that there is a 300W maximum load on this mod. They are using 5 amp SSR’s in many of their mods except the hot water heater mod, where he used a 50 amp.

I’ll keep my UL rated relays that control my 480W of incandescent recessed lighting and my 600W transformer (9 amp draw). At least we didn’t start talking about dimmer loads too.

Here’s the updated site for X-10 mods.

http://idobartana.com/hakb/index.htm

Posted at 1:26 pm on Dec 21st, 2007 by Boyd

i want very fast hacker security for website plz info for me tanks martin .w

Posted at 3:58 pm on Jan 10th, 2008 by martin