Re: MMC resister problem

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Justin Hays by way of Terry Fritz <twftesla-at-qwest-dot-net>" <pyrotrons2000-at-yahoo-dot-com>

Hi All,

(snip from Jim Lux)
> A single resistor across a series combination of capacitors does 
> not provide a safe bleeder function.  It is entirely possible that 
> there may be significant charge on the capacitors.  "Gedanken 
> Experiment":   two capacitors, equal values, charged to 1kV.  Hook 
> them in series, with polarities opposite.  Voltage across series 
> string is zero volts, so putting any resistor across the entire 
> string won't result in any current flow, yet the capacitors are 
> still charged.
> 
> For a MMC, the only safe approach is to put resistors across each 
> capacitor.

There is more than one safe approach, which I mentioned in my
previous post. Again, aside from using resistors across all
capacitors, you can do the following:

1). Use a single HV resistor across the entire MMC
2). Shield the open connections with plastic so there is a physical
barrier.

Doing both of these will keep you safe. Not one or the other, but
both. If you omit the plastic, you could take a shock from the
residual charge on the inner cap's. If you keep the plastic but omit
the main resistor, you could take a shock from other coil components
that are connected to the MMC...(that is, if and only if the
transformer secondary winding goes open circuit,,,in conventional TC
setup).

Take care,

Justin Hays
KC5PNP
Email: justin-at-hvguy-dot-com
Website: www.hvguy-dot-com