Choke Voltage Rating

[mooreamps]

There is probably some reason the core is grounded.

Be-cause . it's . made . of . metal ? ? ?

So its just a no brainer? Ground anything that is metal?

Not necessarily.

How to you think I got a choke to work with my 1.4 KV Beam Power Supply, for my bass amp ?

-g

[GainFreak]

I concluded that the voltage rating is probably just an ass-covering legal move by the manufacturer.

In a similar discussion somebody mentioned the same thing and that he used lots of 400V rated chokes at close to 500V voltages without any failures.

[tedmich]

snip

Also, metal things only need to be grounded if they're somewhere that people can touch them. For the sake of a service engineer, though, live metalwork inside equipment should be clearly labelled.

perhaps a nice fireproof skull and cross bones sticker? or..

[mooreamps]

I've used tube amp chokes with about 7kV RMS at 400Hz across them.

7 KV ? Which project uses 7 KV ?

Also, metal things only need to be grounded if they're somewhere that people can touch them. For the sake of a service engineer, though, live metalwork inside equipment should be clearly labelled.

Yes, if the metalwork had a live voltage potential on it. Otherwise, it's perhaps just another knee-jerk response to an advanced electrical concept you have yet to grasp.

I've once considered, for a few moments, a requirement to apply a static voltage potential to such a device carrying such a large voltage potential inside it, but then concluded it was not required.

-g

[defaced]

7 KV ? Which project uses 7 KV ?

Tesla coil?

[Steve Conner]

Hi all

I have no idea how that L=V/I formula works, and I doubt it's good for anything whatsoever. Someone probably got confused with the formula to work out the critical inductance for a choke input filter.

In a capacitor input filter, the choke value is non-critical. The bigger it is, the smoother it'll filter. In a choke input, see your trusty RDH4 for the formula. For a resonant choke filter, Google turns up posts to ham radio mail lists that explain how to design one.

The 7kV thing was my old Tesla coil, indeed It used resonant charging running off a 10kV DC bus, which charged a bunch of capacitors to 20kV. These were then discharged into the Tesla coil itself, giving a final output of goodness knows how many volts.

You can see the stack of chokes here:
http://scopeboy.com/tesla/tc2closeup.html

and the result:
http://scopeboy.com/tesla/burnt/turbotriodal.jpg