el wire and toroidal transformer.

Discussion in 'The Projects Forum' started by z80, Feb 15, 2015.

  1. z80

    Thread Starter New Member

    Feb 15, 2015
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    ok so i have some el wire i want to put in my cpucase, however i dont want it attached to the psu. so my idea is to have an extra plug for the wall. the inverter i got with the wire is the standard 12vdc input, 160vac output. i have two problems with it. first i think its really kinda dumb to first bring my 110ac to 12vdc then boost it back up to 160vac. the second problem is that the inverter whines like crazy.
    heres the meat of why im posting, im to understand that a toroidal transformer will be much quieter or even silent, vs the little square thing in the inverter. so what i want to do is skip the whole dc step and run my 110ac right from the wall into a toroidal to get 160ac, and then if i can find out how, put some protection on it so the dirty power dosnt burn the el wire.
    my problem is that while i understand most of this, its been 15 years since my last class dealing with this sort of thing.
    so here i want ya'll to tell me why i should not attempt this and maybe if someone understands the science why and how i should do it.
    thank you and go!
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    Ok, I would not pull a thin copper wire with 160 VAC through my computer. Mostly because I use a laptop or pad (people still use desktops?). Anyhow, the low voltage transformer is needed for safety. It likely has current limiting features as well. Yes a toroid can be quieter but there are other things that may be causing noise so no assurances on this.

    Remember, your electrical safety, your home/apartment fire safety and electrical safety (shock) to your PC are all a concern with this completely unnecessary project.
     
  3. z80

    Thread Starter New Member

    Feb 15, 2015
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    ok yes i understand the safety issues and have a healthy respect for 110ac. ive shocked myself quite enough with 110 to be careful, i build what i build and use a remote switch to apply the power on the first couple runs just to keep myself safe. this being said, im not planning on going willy nilly at this otherwise i wouldnt be here asking questions. im considering just giving up since i cant just get a strait answer of the science. i my also just hand wrap a toroidal to replace the square in the inverter. and as far as a current limiting feature i can do just the same with a flash fuse.
    this is at the moment a mental exercise. theory. im interested in solving the problem, thinking outside the box.
    im not asking anyone to tell me how to kill myself just looking at why this is not possibility and maybe problem solve a solution.
     
  4. wayneh

    Expert

    Sep 9, 2010
    12,151
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    The problem is that the EL wire requires 400-2kHz. It is NOT operating at the 60Hz of the mains. That's why you use the inverter.

    I can't imagine how you'd modify the circuitry of the inverter in any way and have it still function as designed. What might be possible is mechanical isolation of the squeal. I believe other inverters may quieter as well.
     
  5. z80

    Thread Starter New Member

    Feb 15, 2015
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    0
    ok thank you! so the 60hz is an issue. i cant remember any device that is just for changing hz. and cant find anything online thats simple for altering hz.
    i could spend a fortune trying to purchase a quieter inverter, but as simple as they are i think i am going to just try building a better inverter. the insides of this inverter is pretty simple. toroidals are still looking like a better solution due to increased efficiency, quietness, cooler, and the ability to use a breadboard before putting the inverter together permanently. ive searched the googles for a toroidal based el inverter and came up empty, same with a search for a guaranteed quiet inverter.
    i think im going to stick with the 12v input in this instance just because i could run it on the psu if i ever put in a cheaper psu.
    my next bit of googleing is going to involve the entire set of electronics inside a wallwart. then ill search for a inverter schematic.
     
  6. wayneh

    Expert

    Sep 9, 2010
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    Just so you know, the folks that play with EL seem to all comment about the noise issue, so it is very common and I suppose it must be a challenge to get rid of. EL power supplies vary in price from ~$5 on up, and I suppose the pricier ones may be quieter.

    As you do your research you will find a LOT of inverter schematics but good luck getting details on how well they operate, in terms of efficiency, noise, adjustability, current capacity and so on. It's not so hard to make one that works, but it may be challenging to get one to work how you want it to. I wanted one that could handle a load of 100mA or so, and I couldn't find one anywhere except at very high prices. So I'm working on my own.
     
  7. ronv

    AAC Fanatic!

    Nov 12, 2008
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    160 volts. Any idea how much current?
     
  8. wayneh

    Expert

    Sep 9, 2010
    12,151
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    The TS wants to light up a CPU case, so I would imagine no more than ~3m of EL wire, and that means 30-45mA at 160V.

    I see Adafruit has added some useful information on this topic. Of note is that the voltage doesn't need to be so high; 120VAC RMS is fine.
     
    Last edited: Feb 16, 2015
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