About to begin my first High Voltage build... What do I need to know?

[aphex]

Besides not to touch the high voltage parts once power has been applied?

 

[Jeff7]

Tesla Coil? Jacob's Ladder? Corpse reanimation equipment?

 

[Red Squirrel]

Keep us posted.

That way if you don't, we know something went wrong.

What is it though? Curious. I've always wanted to build a tesla coil, I just don't have the supplies and room for one. You pretty much have to work for the hydro company to build one. It's the only place you'll get enough power and access to those big pole transformers. (can probably get one that they deem unsafe or w/e I'm sure they get bad ones that still work)

 

[aphex]

Nixie Clock - http://www.tubehobby.com/show_det.php?det=42

 

[DrPizza]

Cool project. "high voltage" though? I thought they were fired by under 200V DC?

 

[compuwiz1]

Remember folks, amps kill, not necessarily the voltage.

That said, more windings.......moar

 

[NL5]

Originally posted by: DrPizza
Cool project. "high voltage" though? I thought they were fired by under 200V DC?

Yeah, I somehow doubt it's running at 600+ volts.

 

[Colt45]

A few mA at 175V isn't gonna knock you down. It isn't exactly comfortable though.

Use grabber type leads, do things with one hand.
http://www.e-z-hook.com/Images/homePageProducts3.jpg

 

[Jeff7]

Originally posted by: RedSquirrel
Keep us posted.

That way if you don't, we know something went wrong.

What is it though? Curious. I've always wanted to build a tesla coil, I just don't have the supplies and room for one. You pretty much have to work for the hydro company to build one. It's the only place you'll get enough power and access to those big pole transformers. (can probably get one that they deem unsafe or w/e I'm sure they get bad ones that still work)

If you want to build a bigass one, then you might want a pole transformer. I built a small one that fits on a board about 1.5 x 2.5 ft, maybe smaller.
It runs on a 6000V neon sign transformer (eBay is a great place for them), and puts out somewhere around 100kV.

My high school physics teacher demo'd a 750kV coil he built. That one was strong enough to light fluorescent tubes several feet away.

 

[Eli]

Originally posted by: NL5

Originally posted by: DrPizza
Cool project. "high voltage" though? I thought they were fired by under 200V DC?

Yeah, I somehow doubt it's running at 600+ volts.

The nixie clock probably isn't, but there are certainly tube amps that do.

Don't worry too much about it. It's not going to kill you.

 

[Stiganator]

..

 

[Jeff7]

Originally posted by: Stiganator
IIRC 10 mA is the FDA limit for current in humans.

I think that's the limit on current flow through your heart. Your skin provides a lot of insulation, though it varies person to person, and moisture on skin can also lower its resistance.
One threat I read about with respect to a Tesla Coil is the primary coil: Its voltage is a bit lower than the secondary (still thousands of volts), and it has sufficient current to allow a spark to burn through your skin. Result: Instant blood contact, and you could be in a bad way if you're grounded.

I never cared to test it.

 

[DrPizza]

Speaking of high voltage, I got myself again with a leyden jar during a lab class last week. 3 labs in a row, I picked up a charged leyden jar, put it down, took the top off, put it back on, etc. The 4th lab, I wasn't thinking, and set the jar back down such that it was electrically grounded. I was electrically grounded. I touched the top. WHAM! Right up the left arm and down the left leg. That sucked.

Usually after I charge it, I discharge it twice using a piece of wire. Then, I allow the braver students the opportunity to complete the circuit using their thumb and pinkie. Rarely is a student willing to do that twice. (Never, until this year.)

 

[JMapleton]

I read this entire thread, wtf are you building?

 

[Jeff7]

Originally posted by: JMapleton
I read this entire thread, wtf are you building?

Originally posted by: aphex
Nixie Clock - http://www.tubehobby.com/show_det.php?det=42

 

[Rubycon]

Originally posted by: DrPizza
Speaking of high voltage, I got myself again with a leyden jar during a lab class last week. 3 labs in a row, I picked up a charged leyden jar, put it down, took the top off, put it back on, etc. The 4th lab, I wasn't thinking, and set the jar back down such that it was electrically grounded. I was electrically grounded. I touched the top. WHAM! Right up the left arm and down the left leg. That sucked.

Usually after I charge it, I discharge it twice using a piece of wire. Then, I allow the braver students the opportunity to complete the circuit using their thumb and pinkie. Rarely is a student willing to do that twice. (Never, until this year.)

Leyden's are amazing. A battery of them (surprisingly called a Leyden Battery) is easily lethal with its direct discharge capable of splitting a large oak plank! :shocked:

 

[CraKaJaX]

Always grab hold of the wires with the back of your hand...

 

[LordMorpheus]

Originally posted by: Rubycon

Originally posted by: DrPizza
Speaking of high voltage, I got myself again with a leyden jar during a lab class last week. 3 labs in a row, I picked up a charged leyden jar, put it down, took the top off, put it back on, etc. The 4th lab, I wasn't thinking, and set the jar back down such that it was electrically grounded. I was electrically grounded. I touched the top. WHAM! Right up the left arm and down the left leg. That sucked.

Usually after I charge it, I discharge it twice using a piece of wire. Then, I allow the braver students the opportunity to complete the circuit using their thumb and pinkie. Rarely is a student willing to do that twice. (Never, until this year.)

Leyden's are amazing. A battery of them (surprisingly called a Leyden Battery) is easily lethal with its direct discharge capable of splitting a large oak plank! :shocked:

A leyden jar is just a big capacitor, right? big insulator so it should be able to get to insane voltages before you have to worry about the insulator breaking down ... but yeah, very small / insignificant internal resistant means that it'll shock you a little more freely than a chemical-electrical battery that has a high resistence to current flow.

edit: that clock looks pretty cool.

 

[Rubycon]

Yes it is.

Even more interesting is one can charge a Leyden jar then (carefully) disassemble all the parts checking the charge to find nothing then re-assemble it and find its poles highly charged! For brave souls only!

 

[CraKaJaX]

Originally posted by: Rubycon
Yes it is.

Even more interesting is one can charge a Leyden jar then (carefully) disassemble all the parts checking the charge to find nothing then re-assemble it and find its poles highly charged! For brave souls only!

How does that work?

 

[Red Squirrel]

When I was a kid I used to take a small transformer (like one of those 12V DC ones) and reverse it to step it up, so it would be like 1:10 stepup. I'd use a 9 volt or other low voltage battery then step that up to charge a capacitor. Then take that capacitor, now charged with 10 times the power of the battery, then hook it up to the low end of the transformer then touch the other end, 10 times the voltage of the capacitor. I don't know why I got a thrill from doing this, but it was probably not healthy.

 

[Eli]

Originally posted by: Stiganator
IIRC 10 mA is the FDA limit for current in humans.

The FDA limit for current in humans? LOL

 

[Red Squirrel]

I've always wondered about the fact that current is the main killer when it comes to electricity. Take a power supply from a PC for example. It steps the voltage down to 12 volts, which means the amps go up. A 12volt fan that is rated at 24 watts uses 2 amps (or does it? I'm just going by the volts*amps=watts formula). I never heard of anyone dying or even getting a shock off a power supply's power.

 

[slpaulson]

Originally posted by: RedSquirrel
I've always wondered about the fact that current is the main killer when it comes to electricity. Take a power supply from a PC for example. It steps the voltage down to 12 volts, which means the amps go up. A 12volt fan that is rated at 24 watts uses 2 amps (or does it? I'm just going by the volts*amps=watts formula). I never heard of anyone dying or even getting a shock off a power supply's power.

That's because 12V isn't enough potential to shock you through your skin.

 

[DrPizza]

Originally posted by: RedSquirrel
When I was a kid I used to take a small transformer (like one of those 12V DC ones) and reverse it to step it up, so it would be like 1:10 stepup. I'd use a 9 volt or other low voltage battery then step that up to charge a capacitor. Then take that capacitor, now charged with 10 times the power of the battery, then hook it up to the low end of the transformer then touch the other end, 10 times the voltage of the capacitor. I don't know why I got a thrill from doing this, but it was probably not healthy.

Since you're mentioning 1:10 stepup, I assume you mean you're using a 120V AC to 12V DC transformer. How'd you reverse it? (since a 9V battery is DC)