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RE: suitable bleeder resistors for MMC
Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Gary.Lau-at-compaq-dot-com>
Your 2000V assumption in the power calculation isn't quite right. Assuming
that 2000V is the peak voltage, the actual RMS voltage will be something
less. The voltage waveform on a tank cap is far from sinusoidal, but
assuming it is, the RMS voltage would be 1414V, and the resulting power
dissipated in each resistor would be 0.2W, a much more comfortable margin.
But I assume your concern was more related to the voltage rating on the
resistors. I have no experience with how much each can withstand, but I
recall that Terry did some experiments a while ago. If 2000 peak-volts
does prove to be pushing things, you could always put two cheap 1/2W
resistors in series for each cap. After all, what could make an MMC more
happy than an MMR!
Regards, Gary Lau
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Friday, February 22, 2002 10:14 AM
Subject: suitable bleeder resistors for MMC
Original poster: "Shaun Epp by way of Terry Fritz <twftesla-at-qwest-dot-net>"
I was wondering what the groups stance is on the 10 MegaOhm resistors that
are used on the Geek Group MMC. If we assume 2000 Volts max and 10 megaohms
across each cap-- the power is only 0.4 watts, but a 1/2 watt resistor, the
next size up, is only rated a few hundred volts. I've seen some resistors
made by IRC that will handle ~ 3kv at 1/2 watt, I'd have to check the exact
specs but they'd work, the only thing was they were very expensive, $3 to $4
Canadian each . What resistors are people using since my MMC capacitors
didn't come with resistors? I want to get some that will be reliable, easy
to get ahold of and cheap!