Switching el wire from Arduino

Thanks for the suggestion Madworm. I have purchased some MOC3031M opto-isolators, and may try that route if I can't get the triac only method only option to work.

However I'm still hopeful of making this work without using an opto-isolator. Others have so I assume it's just a misunderstanding of the circuit on my part. That's what I'm trying to figure out.

Why wouldn't you put the triac on the 9V side of the power supply?

A triac, if I have it right, is specifically designed for switching AC power, not DC.

Putting a transistor in the circuit to switch the DC 9v supply to the inverter is an option. However I eventually want to scale this up so the Arduino is controlling multiple EL wires individually and I would like to do that with one inverter to keep bulk and cost down, while going to transistor route would require one inverter for each length of EL wire (I think).

I typed that too fast. I mean to say an SCR, or for that matter a solid state relay?

Also, the device you show has a 600 volt rating. I'm not too familiar with EL, but I thought it took a higher voltage than that.

A transistor alone might work on the output side, but no matter what you're going to have the problem madworm cited that the high voltage side is isolated from the low voltage side, so your "grounds" are not the same.

I had some success with switching EL wire on/off from an Arduino using a triac, so I'm documenting it here.

This circuit is based on a circuit I found on Flickr http://www.flickr.com/photos/deadhacker/2236794620/in/set-72157603835280870/.

I haven't had a chance to test this extensively, but here's what I've discovered.

Couple of notes:

  • the EL inverter seems to have polarity, the circuit didn't work at all when I hooked it up to the circuit one way but if I swapped the leads it did work.
  • the triac also seems to have polarity, i.e. the circuit only worked with the outer (terminal) pins connected in one of the two possible ways.
  • I found some suggestions that the Arduino needed to be powered from the same source as the EL invertor, I tried both with and without following this rule and both seemed to work fine.
  • I tried several different triacs which seemed to work fine: MAC97A6G, L401E3 and MAC97A6 (all of which have the gate on their middle pin).

While this is better than the circuit you started with I would strongly recommend an opto isolator as madworm said. If anything ever went wrong with the triac then you would zap your Arduino stone dead.

I'm also using EL wire & was wanting to individually switch multiple wires powered from a single power source.

I've got a some moc3041's and have wired one up so a single wire is switched, however, when I try to add multiple moc3041's in order to switch more wires, all the ELwires go on/off rather than individual ones....

can somebody give any tips? point to a schematic?
I'll post a pic in a second.

Cheers!

And here's a circuit (that works) where a single wire switches on/off. The two green wires coming in from the right hand side are the AC power supply. The black cables feed the EL wire.

ABOUT TO ADD DOUBLE SWITCH IMAGE

when I try to add multiple moc3041's in order to switch more wires, all the ELwires go on/off rather than individual ones.

Can you post a schematic of the system that doesn't work, that way we stand more of a chance in seeing what is wrong.

Here's the circuit doesn't work that switches both EL's when I want it to switch them individually....

Sorry can you post a schematic a picture is no good in seeing if you are trying to do the right thing, it is only good for seeing if you have implemented what you were trying to implement.

This is what i'm trying to make:

any help?

Did you make any progress on this? I'm pretty much following in your foot steps. I've picked up some opto-isolators and triacs from mouser that were used in a couple other EL wire projects.

I'd like to be able to individually switch each strand i have connected. Any luck with that?

Also are you using a seperate power source for your inverter? I wanted to use a separate 9V source with its own power and ground. Is that possible or do i still need to have them all connected to the same ground as the arduino?

bump ;D

I just got an Arduino for the sole purpose of controlling multiple strands of EL wire

I didn't manage to get that schematic to work in the end - I was on a deadline so ended up switching two power supplies - really inefficient I know, but time beckoned. Can anybody else shed some light as to why the schematic didn't work?

By the way, I found this on sparkfun:

Its called the EL Escudo and is a shield for the Arduino.
Seems to do exactly what I want, although it is limited to having only 2 of the el wires active (or all of them) at the same time.
I may purchase it and see how it works.

I'd like to point out that others have reported the library that SFE supplies simply doesn't work. I'm using the EL Sequencer (non-shield) which has the Arduino bootloader on it. I have very little weekend time, but I'll try to keep you updated.

As for only being able to turn 2 wires on at a time, that's a pretty easy fix: Just turn them on and off, very quickly. Think POV.

I was having trouble switching el wire using triacs and optocouplers but I did have success using a solid state relay.

in tomski's picture it sure looks like the resistor is Red,Red,Red 22x10^2 = 2.2k Ohm but that blue wire next to it is in parallel so the resistor acts like it isn't even there.