Reader needs some help.

[Michael Kaudze]

Hey Guys,<p>I got a question from some guy, I dont really know why I got it- Im not technical like all of you. So if anyone could help him out it would be appreciated. Here is his problem: Thanks Guys! Myk.<p>In your article about Flyback Transformers, your F.B. Transformer was running in air as all of the F.B. Transformers seem to be.

I wanted to increase the output without arcing to the core, so I put the primary-core-secondary in oil, and it never did work - but blew out the driver immediately. Hence, my question: Won't they work in an oil bath?

No magazine response, please - Just an e-mail back would be greatly appreciated!

Thank you!
Annalisa

[email protected]

[jimandy]

What's this all about? Do I need to read the article to understand her question? I sure don't want to fiddle with the flyback in my TV set, least of all put it in an oil bath!<p>Did the article suggest modifying the flyback for higher voltage?

[haklesup]

What kind of oil and did your friend try to increase the output at the same time?<p>Can we assume that a proper non-conducting, high dielectric fluid was used. Just any old motor or cooking oil probably won't work.<p>You could do some experiments on the "Oil" to see if it is appropriate.<p>1. Measure the resistivity. Any current leakage would make the fluid unacceptable. You should use a Hi-Pot meter and look for more than G ohms<p>2. Test to see if it affects permitivity. Construct an air core inductor and measure its inductance. Submerge this inductor in the fluid and measure the inductance again. It should be the same. Any change now will change the way an air core FB transformer would work.<p>If your friend tried to increase the output at the same time, it may have been too much for the insulation on the wires of the transformer itself. You can put it in all the oil you want but if coil is tightly wound, the oil will not surround and insulate the wire, only the varnish on the wire is the dielectric.<p>Putting HV components in dielectric fluid will reduce corona and arcing at the output of those components and between components but may not help with the V ratings of those components themselves.<p>Depending on what he is trying to do, he may need to substitute the FB transformer for one with a higher V rating or if Corona and arcing are the concern, corona dope or even parafin wax can be used topically to insulate terminals.

[Michael Kaudze]

Tell you the truth, I didnt read the article he is talking about and I have no idea what he is trying to accomplish. I was hoping some one here did and knew what he was talking about... I'm just trying to relay his words in hopes that I could help him out some what. Thanks for the input haklesup.

[Mike6158]

Sounds to me like someone was trying to build a cheapo Tesla coil or something. <p>All of the good stuff has been said. Bet a dollar he used cooking oil or motor oil or something like it.

[Edd]

I also would also concur that person was trying to stretch the limits in high voltage production. His thought process probably being on the external terminations of the voltage , since as was mentioned , the initial design of the transformer with its insulation type, along with its inter spacing, as well as clearance to center core left a minimal leeway in stretching of those breakdown parameters.
Also, unless he found an old relic “flyback” transformer from the ‘40s up thru the last of the tube designs in the 60’s,that restified the high voltage with a separate rectifier, he would instead, have been using an integrated high voltage transformer…IHVT…with the DC high voltage components being designed/contained within the potted casing also. The configuration being in a DC high voltage tripler arrangement from the derived high voltage AC produced at the transformers high voltage output. This results in a smaller, more reliable high voltage winding, since it can operate at 1/3 of the potential, but it does leave little leeway on the PIV breakdown specs of its internal diodes if overdriven high voltage wise. Upon their breakdown, the secondary winding becomes a “shorted turn” on the whole transformer and seriously loads down the primary circuitry with skyrocketing current demands until final failure or its power disruption by fuse failure, etc. <p>73's de Edd
[email protected] ..….....(Interstellar~~~~Warp~~~Speed)
[email protected]…......(Firewalled-Spam*Cookies*Crumbs)

[haklesup]

One more thought.<p>In the past, the most effective dielectric oils contained PCBs which we now know are cancer causing. This guy (or gal if annalisa is the name) shouldn't attempt to recycle oil from an old industrial transformer or their efforts to avoid a shock will pay off in an early demise.<p>If the desire is to improve on air by displacing it with a substance of higher dielectric strength, then there are many safer (though no less messy) alternatives. Just google on electronic potting compounds

[terri]

Cooling....? (Or lack thereof.)<p>Frequency...? (Molecular resonance with the oil bath.)<p>Wet oil...? (Oil does aborb water slightly.)<p>Misconnection...?<p>I wonder how "instantly" instantly was.<p>Jes' noodling it around. Brainstorming, don'cha know... hyperbolizing outta the orbit.<p>[ February 24, 2005: Message edited by: terri ]</p>

[Michael Kaudze]

You guys rock! Thanks again for the help.

[dacflyer]

most all transformers here now days use mineral oil..i do not know if something different is used for super high voltages...
good luck

[Chris Smith]

The voltage limits of any coil are based on the length of each coil winding over actual voltage in the circuit winding, and its proximity to each nearby coil winding on the same coil [shellac thickness], divided by the break down voltage for the shellac on the wire that makes up each winding.<p> Oil wont get in between each winding where it counts to add to the insulation value, and so it will arc the tiny distance between touching windings until catastrophic failure occurs. <p>Same thing happens when a Micro wave oven "arcs" from metal objects placed inside, [not all microwave ovens] and the electric value of the Microwave energy is fed back on the Magnatron windings, breaking down the tiny insulation in hot spots and eventually shorting out the transformer windings by cooking or arcing the shellac until a failure occurs.