New ESL panels clicking

[dochungwell]

Hello All,

Well much has happened since I built my first ESL's earlier this year (the bug has bitten hard!) but I have now an issue.

I have built about 10 panels and I seem to have a 33% failure rate and the failure is usually the same, a constant steady approximately 2 clicks per second sound. The source of the failure is definitely with the panels construction, but exactly what I can not pin point!

Yesterday I constructed 3 panels, and one failed making the sound as I descibed earlier. since this the exact problem/panel failure we had during another run I would like to know what exactly is the source of the failure so I can correct this.

we are at the point where we can simply tear it apart and build another, but I would really like to correct the problem and learn just whats the cause....?


Thanks
Doc

[kevinkr]

I'm assuming that the clicking is the result of a tiny arc somewhere inside the panel. Probably somewhere on the frame particularly where the polarizing voltages and drive are applied. Perhaps you can see it occurring in a dark room or if you increase the available current from the HV supply.

[geraldfryjr]

Did you do a High Yoltage stress test of the whole surface of the stator before you assembled it?

What happens if you lower the bias voltage?

It seems that there may be some leakage of the stator coating and is arcing somewhere.

Does the diagphram stay stable or does it collapse to one of the stators and then snap back ?

jer

[dochungwell]

Both reasonable questions, first i don't think it is arcing since I have experienced this bacon sizzling sound. This sound remains constant throughout the panel and no arcing is seen in the dark.

Jer, I have done the Arc test in the past however I read on this forum that sanders believed an uncoated /insulated panel would work fine. To answer your question with regards to the diaphragm collapse...I have seen that issue as I had one panel fail when i tried to salvage a panel by "hand stretching a corner that peeled up".....it was visibly stuck to one side.

The leakage sound plausible but I built 3 in a row all exactly the same, could some of the Licron possibly leak past my 1/4" mask and is shorting against the stator?

[fperra]

How about your step up transformer is arcing?

[geraldfryjr]

Yes ,Jerry ,overspray can be a Factor, As it is something that I try to keep control of by heavily masking every thing before spraying the coating, it is very undetectable by sight.

Since it is permanent I have not yet had the chance to test if any solvents can/or will wash it off.
I have used Denatured alcohol to clean them with know degradation in the coating.

I have had a similar issue happen as when I started to raise the bias it would crackle through the midrange of the voltages until I get to full voltage and then then the crackling stopped.
I was then able to vari the bais voltage without the crackling throughout its range 0v to 7kv.

I have not yet determined the reason for this yet except that there must be some leakage some where and when the voltage gets high enough the difference in the imbalance becomes low enough to stop the arcing.

I have found that even after discharging the panels that they still worked and it took them a few days of no bias voltage at all to finally stop producing sound of any kind until the bias was re-applied.

This is most prevalent on my White painted panels as I can't seem to use a bias more than about 3.2kv because the white paint starts to conduct at levels above this regardless of its thickness.
And they start to click as you are describing and lowering the bias voltage on those panels makes it stop.
This is why I had stressed that you can't have the coating to thin and more is better providing that the pigments don't cause it to conduct.

Even with such a small leakage this can happen and it will sound large as it is moving the whole diagphram.
You may not be able to detect it by eyeball and will be very hard to do so.
Some of them I could see and a lot of them I couldn't.
And it just seemed that the more clear coating I had put on, the better it got,until a certain point of course.

Also I just remembered that you are in Florida and that the humidity may be an issue as well,But this is something that you will have to determine by the use of your other panels as a control.

Does it do it all of the time or does it eventually stop?

jer

P.S. Any kind of sharp edge or points are the biggest culprit regardless of how thick the coating is sometimes, as my worst mishap and arc over occurrd at the edge and was a from a sharp point that was buried in some insulation but not deep enough apparently.

[chinsettawong]

I have a similar problem before, and it comes from the power supply. In my case, one of the transformers that I connect back to back in the power supply is getting bad and eventually burnt. After I replace that burnt one, the problem goes away. You might try to check to see if your transformers are getting hot.

Wachara C.

[CharlieM]

Hi Jerry,
If you used the same type of diode/cap ladder power supply shown on my blogpage, you might want to try reducing the bias voltage by tapping into a lower rung on the ladder.

[dochungwell]

Hey Guys!

Good to hear from you all,

Jer, I would agree that it is likely a leak somehow from the Licron sprayed diaphragm to the front panel. Switching cables and power from the other channel revealed it was an isolated issue affecting only that panel, and since I am doing a production run of another 8 panels, I have several to test from. I am trying to figure this phenomena.

Oh BTW, Jer I the humidity level is very high....outside, however we were fortunate enough to have AC installed just after we got indoor plumbing, I was also getting a rash from the banana leaves.....LOL

Today I will play with the suggestions from Wachara C., and Charlie M with regards to the power supply. I don't actually believe this is the issue however since this is my second failure with the exact same symptoms I believe it could be related to the power connections to the spade connectors, or the panel itself...I will report back shortly from the banana republic as we all know as Miami.... LMAO

Jerry/Doc

[CharlieM]

Originally Posted by dochungwell

...Switching cables and power from the other channel revealed it was an isolated issue affecting only that panel, and since I am doing a production run of another 8 panels...
Jerry/Doc

When you say you switched out the cables and power, does that mean you also switched out the step-up transformers? I'm very curious about your clicking problem and hoping the source isn't a arcing across the transformer windings.

My concern is that I had only briefly sound-tested those Antek trannys before posting them on my web page. They sounded great and didn't go up in smoke when I momentarily pushed the volume to insane levels-- but I also haven't thoroughly tested them over time in real-world use. I would not want to continue recommending those trannys if it turns out they are the source of your arcing problem.

Keep us posted, please, Jerry.