Electroluminescent wire via an optocoupler

Hi all

A bit of background: I'm a very new to Arduino and have very hazy electronics knowledge! This is my first post too...

I have a few lengths of electroluminescent wire each with a battery pack (The wire is the 2.5mm wire on the Surelight website - sorry I can't include a link on my first forum post apparently!) and also the KD5 battery pack at the same site.

I am trying to set up an Arduino sketch that will light each wire in turn, i.e. in a sequenced pattern.

So far I have managed to get one EL wire / battery pack lighting up in a timed fashion. I have a very simple circuit basically straight from the Arduino board across a 4N25 optocoupler and over to the one of the wires between the battery pack and the EL wire itself. I believe the optocoupler route is a sensible one? Maybe I'm already off on the right foot though...

In any case, the problem is that the EL wire is then is very dim compared to when the optocoupler is not involved.

I have noticed that the output voltage from this particular optocoupler is not up to scratch (it seems that the battery pack is an inverter that turns the 6v of battery into 120v of AC which exceeds the rating on the 4N25 spec sheet). So I have identified another optocoupler with a high output voltage rating. However, there are all kinds of other variables that I'd rather not have to tackle through trial and error! First is current (Unfortunately I cant test AC current with my multimeter I dont think) and secondly I wonder whether frequency is an issue. And this is before I attempt to attach four separate units, with an optocoupler each.

So question is: What optocoupler units (if any) should I choose? And are there any other considerations? Any advice or thoughts welcome!


a 4n25 style optocoupler has a transistor at its output, and will probably effectively rectify the AC power that EL wire likes to use into a pulsating DC that won't work nearly as well. You might have better luck with a triac-style optocoupler like like a MOC3022; in theory it should be able to drive low-current things (like EL wire) directly, even though it's usually used to trigger an external triac (using one without the triac for driving EL wire has been something I've been meaning to try, but haven't gotten around to.)

Looking at Sparkfun's shield design seems like a good idea...

Hi all

Thanks for the feedback on this! Having postponed my project, I'm just coming back to it now and only noticed these replies!

I took your advice Richard and bought the Sparkfun shield.

One problem is that the inverter they recommend doesn't seem to be available in the UK, where I am.

I have two inverters that I'd potentially like to be able to use. One is wrapped up with 4xAAA batteries in a pack - 'KD5' here - http://shop.surelight.com/EL_wire_inverters_2-10metres.htm

and the other is a standalone inverter which I currently am running from a mains outlet - 'L30' here http://shop.surelight.com/EL_wire_inverters_10-50metres.htm

With what I have (or indeed, an alternative inverter available in the UK!) would you guys be able to describe how I can set up the Escudo board to be able to power up to 20m EL wire? I am certainly no electrical engineer - so baby steps please!

Also, I have been reading the conversation at http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1269524229/all but it seems to refer to a 5v inverter (and no one seems to have had much luck there either..)

Many thanks in advance