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What do I need to know about high voltage? Answered

I'm planning on doing a little bit of high-voltage work ( see my plasma cutter question), and I know most of the theory ( except why HV AC in power lines wants to go to Earth ground--any answers to that are welcome. I have my own theories, but...), but I have really no practical experience at all with high ( 50,000 volts) voltage, i.e. what gauge of wire to use, what gloves to wear, how to ground a metal container, etc. Any advice is welcome. Thanks!


In answer to your question about wires, for HV you need real silicone-insulated HV-grade wire, not ordinary wire. Arcs can easily jump through the insulation on an ordinary wire.

But microwave oven transformers are awfully dangerous. If you touch the leads just one time -For a split second- it will kill you. You should not do anything with them unless you have a good experince with HV.

I would suggest starting with an ignition coil driver(not very dangerous) to get some experience, and then do a flyback driver(these can give you great shocks and nasty RF burns, but are not lethal), and once you are familiar with the safety procedures, actually do something with MOTs.

P.S. There are lots of instructables about ignition coil and flyback drivers, to get you started.

P.P.S. If you want a list of the safety procedures ( I couldn't name them all, even if I practice them daily : this gets to be an habit, after some time), google something like "high voltage electrical safety"

Have fun and be safe,

Is it rectified mains power? Is it a battery? No, it's SuperCapMan!

P.P.P.S : Gloves are pointless. At these voltages, an arc will jump through rubber/leather/about anything like it was nothing. Actually, you should avoid getting HV-grade wires touch together because even silicone will break down past a certain limit. Also, why do you want to ground a metal container?

Have fun and be safe,

Is it rectified mains power? Is it a battery? No, it's SuperCapMan!

thanks for your advice, everybody. It's been realy helpful. Although I do want to say, death defyer, that it actually only takes about 0.5 amps to cause heart failure. I'm going to keep researching, etc. Also, how does one get/prevent RF burns? I've read alittle about them, but I heard them described in the same sens e as "ether" was before Einstein: omni-everywhere, all-permeating throughout a high voltage experiment, which i don't get. Any info on that is appreciated. Thanks!

Sorry about that. It takes about 50 miliamps to cause heart failure ( I just heard on the Science Channel). However, you should never even consider conducting any sort of electricity through your body at all anyways.

About RF burns: you get them when skin comes close/touches a HV, high frquency wire(above a few KHz). The way I understand it is that the RF emmitted by the wire induces a current through you skin, and the electrical resistance make that you get burn by ohmic heating.

The most obvious way to avoid this is to keep all parts of your body far from HV wires(duh!). This isn't a problem with mains frequency (60Hz here in Canada), but if you build a flyback driver, watch your hands! RF burns are painful.

Have fun and be safe,

Is it rectified mains power? Is it a battery? No, it's SuperCapMan!

Which HV instructable(s) have made most sense to you so far? L

To lemonie: Most HV instructables make sense to me, as in I understand them, but I was mainly wondering how to gain knowledge and experience safely working with HV, mainly because everybody says that you need HV experience to do any HV work, and I wanted to know where to start. Thanks!

I was trying to get a handle of where you were coming from. If most of what you've seen says "you need experience" they're essentially saying "no liability". You need to have some sense of HV to ground, that is having ground/earth connections that you can look at and say "that's the most favorable path" (i.e. not me). You also need a basic "is it on or is it off?" understanding, but that's fairly obvious. The best rule is to stay well-clear. As for ground connections, you domestic wiring should have one. L

voltage isnt what kills people it is amperes. if it is high voltage it probably will have a high amperage but most likely not. If you are working with high frequincies then you wont feel anything if it shocks you and last of all it takes 1 amp to kill you not 20 ma that just hurts

It sounds to me like you really don't know what you are doing. 50kV at tiny current levels deliver an awful lot of power. 20mA through your heart will kill you, and 50kV can drive that easily. Like I said in your plasma cutter question, you don't NEED high voltages, just very high currents to maintain an arc (which is a low voltage phenomenon anyway). You need to describe exactly what you are doing. You need insulated tools and a method of absolutely discharging your rig so there is no chance of residual charges getting you - note that capacitors, particularly electrolytics have a phenomenon of charge recovery, so even when you think they are dead, you can have a nasty shock... 50kV will jump anywhere between 25 and 100mm on its own, in air - a lot depends on the shape of the "hot" bits. Be very careful or be very dead - from all but essentially static sources, these are the choices. At least work only one handed. The answer to your question about power lines is capacitance. Steve

all i know is that it hurts when u touch it