Can PVC Prevent Static Charge from Grounding in Mylar Setup?

[Matt1]

I am using a negative ion generator module that I purchased to generate a static electric charge in a 4' x 7' aluminized mylar blanket. I made a cage out of 3/4" PVC tubing to hang the mylar from (vertically) - I want to suspend the mylar from the PVC so that the mylar is insulated from any conductors that would conduct the static electric charge to ground which would prevent its buildup in the mylar sheet. The PVC cage sits on a carpeted floor in my house.

I am trying to figure out if using PVC under these conditions will prevent the flow of electricity to ground which will allow buildup of a static electric charge in the mylar sheet. My concern is that electricity will flow to ground and damage the negative ion generator device by overheating. PVC is an insulator and, as such, will not conduct electricity to ground, but will accumulate a static electric charge. However, if a static electric charge develops in the PVC, could it conduct to ground by virtue of the fact that the PVC is sitting on carpet with a wood floor underneath? Isn't the potential there that the static charge could spread through the PVC, carpet, wood floor and ultimately a conductor that would flow to ground? Also, could coronal discharge (ionization of surrounding air) allow conduction of charge from PVC to the floor underneath - again resulting in grounding and burnout of the negative ion generator device?

The first negative ion generator module I purchased overheated and burned out; the plastic on the side of the case melted. I have a replacement of the same model and I have tried to make sure the high voltage output of the device does not have a path to ground. I monitored the device and noticed that it got progressively hotter, so I shut it off. It was not too hot to hold, but it was hot. Does anyone know how hot such a device should get? It is a 20kV model.

Thanks

 

[DrZoidberg]

If it overheats run it with a lower voltage or put a resistor between the battery and the generator.

 

[Matt1]

I tried it again and it became progressively hotter until it was almost too hot to touch, so I shut it off. The module already has internal resistance, I think, to limit the amperage. I am wondering if the mylar sheet is too large for the device; maybe it is working too hard to try to charge the mylar and is overheating in the process. Or, maybe the unit is designed to become very hot, maybe the windings can tolerate it.

 

[jim hardy]

Does it overheat when not connected to your mylar sheet ?

Basic troubleshooting - draw a logical circle around your problem, then progressively tighten the noose.

http://www.pvc.org/en/p/electrical-insulation-characteristics

 

[Matt1]

I actually did just that. I connected the 10kV output of the device to a smaller plate, a 12" x 12", 22 gauge galvanized steel sheet and the device got just as hot, not quite too hot to touch. It must be designed to run at high temperature. Being a high voltage transformer, it must generate a lot of heat.

Thanks for your reasoning. I held everything else constant and changed the variable of plate size to test the hypothesis.

Matt

 

[DrZoidberg]

You should try and insulate the output. Wrap lot's of plastic foil around it so you won't have any output current at all.
Also it is possible that your module is designed to be mounted to a heat sink. Or maybe you simply run it with to high an input voltage.

 

[Matt1]

Do you mean insulate the output end of the device itself or the entire length of the output wire (which is insulated 18 gauge copper wire leading to the plate). I'll use a heat sink.

Thanks, Matt

 

[NascentOxygen]

Do you have a circuit diagram of the module? A photo of both sides of the module might assist, too.

 

[Matt1]

Dr. Zoidberg,
You were right about insulating the output. I wrapped plastic around the output wire where it was connected to an 18 gauge extension wire by a wire nut. I had electrical tape around the wire nut, but I think high voltage charge was leaking out at this spot because I could hear frequent clicking or slight popping. When I wrapped this spot in plastic and taped all around it, the popping almost completely stopped. The device still gets just as hot.

I still wonder if the extension wire (insulated 18 gauge) leading to the plate would benefit from being wrapped in plastic. This wire moves in repulsion when I bring my skin close to it; there seems to be a field around it.

The schematic is available at amazing1.com - YD013SD18 Negative Ion Driver.

http://www.amazing1.com/content/download/YD-013SD18_Instructions.pdf

 

[jim hardy]

I still wonder if the extension wire (insulated 18 gauge) leading to the plate would benefit from being wrapped in plastic. This wire moves in repulsion when I bring my skin close to it; there seems to be a field around it.

you might visit an auto parts store and get a yard of spark plug wire.
Clear silicone caulk makes a good insulator. Trade name is RTV..

 

[NascentOxygen]

The schematic is available at amazing1.com - YD013SD18 Negative Ion Driver.

Unfortunately, a blank rectangle labelled DRIVER is not a circuit diagram.

You have seen the warning stating that the output wire is directly connected to the mains and is an electrocution hazard if it is placed where someone may come into contact with it?

 

[jim hardy]

Unfortunately, a blank rectangle labelled DRIVER is not a circuit diagram.

You have seen the warning stating that the output wire is directly connected to the mains and is an electrocution hazard if it is placed where someone may come into contact with it?

wow good catch N O .

Matt - Check with an ohm-meter to see how it's connected to input . My guess is it's tied to neutral somehow, if so a receptacle wired backward would make it dangerous.

Neutral is the wider of the two power cord's flat prongs.

If you find it so connected, this project might be approaching PF's threshold of a dangerous undertaking.

 

[Matt1]

When I wired the 2 input wires to a 2-prong plug, I questioned if each wire went to a specific prong on the plug, but the supplier I bought it from claimed it didn't matter.

I have a circuit diagram that was emailed to me by Yuida compay, but it is a .doc file and I couldn't upload it to the forum. If there is a way to upload the file I will.

I have a meter, buy I don't know how to test for the neutral input.

I will leave it alone until I know the inputs are wired correctly.

 

[DrZoidberg]

You can add attachments to your posts. If your file is not accepted try making it a zip file first.
Also it would have been a much better idea to buy the 12V version of the device. It has a smaller output current but it's safer to play around with.
What do you want to do with this anyway? Build some kind of lifter? The pvc tubing is going to be too heavy for that.

 

[NascentOxygen]

When I wired the 2 input wires to a 2-prong plug, I questioned if each wire went to a specific prong on the plug, but the supplier I bought it from claimed it didn't matter.

The diagram shows 115VAC. You wouldn't happen to be in a 220V region? That would be an easy explanation for its excessive overheating.

 

[Matt1]

The shock hazard, I think, refers to the black output wire labeled as Ground. This wire seems to be for optional attachment to a dust collection plate which is used to collect the negative ions generated by plate attached to the 10kV output. Electrons from the statically charged negative plate will ionize air molecules, these anions will then flow to the positively charged plate which is energized by the black output. Because you have this anionic flow from the negative to positive plate, you might be able to create a static electric field between the 2 plates.

When it was running, it appeared to be working because when it was dark, I saw small flashes of light on the "dust collection plate" which may have been airborne negative ions impacting it.

I do not live in a 220V region; it's plugged into 120VAC.

Is the 12V version safer because the input and output is safer?

 

[jim hardy]

I have a meter, buy I don't know how to test for the neutral input.

Does the power cord have three prongs or two?

Select "Ohms" or RX1 or RX10 on your meter.
The meter should indicate high ohms, or if it's electronic it should show overload.

Connect the meter's two test leads together. The reading should change to a very low value.

Now you know the meter at least works.

Next make sure your ionizer has been unplugged long enough to discharge. Maybe twenty minutes.

Make a sketch of that thing and its wires.
Now connect one meter lead to one of the flat prongs of the power cord.
Connect the meter's other lead, one at a time in turn to each and every other wire on that gizmo.
Write down what the meter reads.
You should get a reading only to the other prong of the power cord, and maybe not even there..

Now swap meter leads and repeat all those readings. That checks with opposite polarity.

Now move meter lead to the other flat prong of power cord and repeat all measurements, both polarities. Again write down each reading.

If there's a third prong for ground, repeat readings both polarities. In the US the ground prong is u-shaped or round and slightly longer than the flat ones. Extra length is there so it's first to connect and last to disconnect, for safety.

If either flat prong of the power plug reads to any of the output wires, that gizmo isn't safe. It needs to be completely enclosed in a nonconductive box of some sort.

Right now a lot of these "Room Air Purifiers"
http://www.homedepot.com/catalog/productImages/65/41/415dbd02-800a-46f4-a3ac-06ca7914e577_65.jpg
are being discarded because of noisy bearings.
http://www.homedepot.com/p/Vornado-Whole-Room-HEPA-Air-Purifier-AC300/203480168#customer_reviews

They have a nice plastic enclosure with no exposed metal, and a powerful fan.
The bearing is an easy two dollar fix, check the customer reviews but click 'by most recent'
Maybe you'll run across one that's been discarded, like i did.

 

[NascentOxygen]

The shock hazard is an electrocution risk if you get between mains active and ground or neutral. Your diagram back in post #9 shows a solid conducting path from the ion emitter wire to the ground plate through a few diodes (and paralleled capacitors) in the voltage pump. This will expose 115VAC* if it's your unlucky day.

* half-wave rectified, practically

 

[jim hardy]

Okay

your .zip file in post 16 is a MSWord document that more correctly calls the black wire "0V"
inferring it's just circuit common for the hv side, not "ground" (i detest that term)

which should be well insulated from the mains, and you'll verify that with your meter.

And it shows a bleed-down resistor across output, maybe that explains its running warm.
You might ask the merchant who sold it to you how warm they typically run.

And it shows a two conductor input cord. So there'll be no ground prong on the plug.

And i assume the case is nonconductive plastic?

 

[Matt1]

Jim,
I'll do the tests with the meter. Will the results of the tests also tell me if the two input wires are specific to a particular prong on the two-prong plug? The case is plastic.

Thanks to everyone.

 

[jim hardy]

Jim,
I'll do the tests with the meter. Will the results of the tests also tell me if the two input wires are specific to a particular prong on the two-prong plug? The case is plastic.

Thanks to everyone.

hopefully they won't.
The two black input power wires ought to be very well insulated from all the output wires , but might give a small reading between one another.

Look carefully at the black two conductor input power wire . Hopefully it's lampcord as shown in your zip/ Word document.
One of them should have a real small "rib" along its length, and that is the "neutral" if they hooked it up correctly inside. The neutral goes to the wider of the two prongs on your plug (if you're in US).


Most lampcord is marked with that rib but it's so small most folks don't know it's there. So a lot of lamps get mis-wired. I once bought one brand new that was mis-wired.

old jim

 

[Matt1]

The two input wires are just regular insulated 22 gauge wire; they aren't lamp cord with a rib, so I can't differentiate them. I definitely need to identify which one is the neutral so that it can be connected to the correct prong on the plug? Or is it possible that it doesn't matter which prong each input wire is connected to?

 

[jim hardy]

The two input wires are just regular insulated 22 gauge wire; they aren't lamp cord with a rib, so I can't differentiate them. I definitely need to identify which one is the neutral so that it can be connected to the correct prong on the plug? Or is it possible that it doesn't matter which prong each input wire is connected to?

If you ohm meter shows no connection between either of those two wires and any output wire
i think we can assume that's what they intended.

Still - be careful with that thing . Enclose it so tiny fingers won't find the metal parts.