EL Inverter Silencing
aka a method to make an EL inverter much more quiet

Here's an inverter out of the case. This is probably the correct time to note that: Doing this probably isn't very safe. You risk breaking the inverter and/or damaging your power supply. I'm sure this mod has negative effects on the longevity of the inverter at the very least. Also, as always, use common sense. EL inverters create high voltages. Your mileage may vary. End of lecture. Let's check out the hack.

EL inverters put out a really irritating noise. It really annoyed me that I had set out to build a silent Linux box and my main case mod gave it an annoying high-pitched whine. I would be really curious to see what others have done about this problem.

Before trying this hack I bought an inverter from a website which claimed to sell "silent" inverters. Unfortunately, when the new inverter arrived it turned out that although the inverter seemed a little bit more quiet, it was also higher-pitched and thus way more annoying. Back to the drawing board.

After building a couple of foam boxes in an attempt to muffle the inverters, I still wasn't able to get any of them as quiet as I would have liked. One day while I was trying different things, I noticed that if you put an inverter in a PVC pipe and sealed the ends, the noise was cut off quite well.

The problem with putting an EL inverter in a sealed PVC pipe is that they can get really hot, so putting the entire inverter in a section of pipe and then sealing it wasn't a practical solution. Later I had an idea. I theorized that most of the heat was probably coming from the resistors and capacitors, and most of the noise was probably coming from the coil.

Only way to test the idea was to take the coil off.

Once the coil was off, I took five pieces of wire about three inches long and soldered them to the coil. Three inches is probably a good length. Heat shrink tubing all around.

I used heat shrink tubing on everything, and re-attached the coil to the circuit board.

After this, I hooked eveything back up again and ran it for a couple of hours. I found that my theory had been correct. As a matter of fact, the coil doesn't seem to heat up at all and it generates almost all of the buzzing.

Since the coil doesn't get hot, it's safe to seal it up in something. I built a chamber out of PVC. For extra insulation, I put some 1/8 inch thick hobby foam on the inside of it. My goal was to make it sealed up well but definitely not airtight.

Here's the completed PVC silencing chamber. I put the rest of the components back in the original case and fired it up.

Success!