Re: which type for bleeder resistors?

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <HomerLea-at-aol-dot-com>

There are tigerstripe 44 meg 7.5 kv $1 each and 100 meg 15kv 3 watt $.50 each
in batches of 10 or 20 on ebay regularly. The seller keeps relisting them every
other week.
Jim Heagy



>
> > 
> > Tesla list wrote:
> > > 
> > > Original poster: "Laurence Davis by way of Terry Fritz
> > <twftesla-at-qwest-dot-net>" <meknar-at-hotmail-dot-com>
> > 
> > > are these overkill, or just what I need?
> > > I've never had to price megohm resitors, but the price seemed high to me.
> > > (the caps are cheaper than the resitors!?)
> > 
> > You can use regular inexpensive 10 MOhm resistors. Their size is
> > important, but if you keep, say, 1000 V per capacitor/resistor,
> > anything with more than 1 mm of length will work. I made an MMC
> > using small 10 M resistors (1/8 W?), with two in series across
> > each capacitor for better safety. They work well, at 1000 V per
> > capacitor, not even getting warm (they dissipate at most 12.5 mW).
> > 
> > Antonio Carlos M. de Queiroz
>
> If they are 1/8W, it is not a good idea. Their resistances *will* 
> tend to go high and eventually open-circuit over time. The problem 
> with that is that an excessive voltage burden will be thrown onto one 
> of the caps.
>
>        I fix SMPS all the time where the manufacturers thought they 
> could get away with using under-rated resistors in a high voltage 
> situation.