Re: Bleeder resisters

["Mike Harrison" <mike-at-xxxxxxxxxxxxxxx> (by way of Terry Fritz <twftesla-at-xxxxxxxxxx>)]

On Fri, 10 Nov 2000 07:46:18 -0700, you wrote:

>Original poster: "Neil Chambers" <Neil_Chambers-at-paragon-it-dot-com> 
>
>So how important is the "working voltage" rating of the resisters? Do I need
>to get high voltage ones (>1000V) or will the usual c.250V ones do?
I don't think it's worth risking problems later for the sake of a
small increase in cost to use the correct resistor type. 

>Original poster: "Ted Rosenberg" <Ted.Rosenberg-at-radioshack-dot-com> 
>
>Mike: I can't say you are right or wrong. All I know is these resistors
>normally sell for 9 cents in smaller quantities. And the bottom line is all
>100 are just fine in the MMC being used in my 900 watt coil under heavy duty
>cycles in the haunted house just ended. The coil performed flawlessly 5
>hours a night for most of the month. and the entire block of caps never so
>much got warm.
>
Of course almost any device will work in excess of its ratings, but
you never know how much headroom you may or may not have.  Unless you
know for sure that the resistors you are using have the required
rating there will be some risk of failure. As bleeder resistors are to
some extent safety-related, and the correct ones are not expensive in
absolute terms, I see no good reason not to use ones with the correct
rating. 
 
>Ted
>
>Subject: Re: Bleeder resisters
>
>
>Original poster: "Mike Harrison" <mike-at-whitewing.co.uk> 
>
>On Thu, 09 Nov 2000 11:36:23 -0700, you wrote:
>
>>Original poster: "Ted Rosenberg" <Ted.Rosenberg-at-radioshack-dot-com> 
>>
>>Neil:
>>Based on what I picked up from Terry, the bleeder resistors are designed to
>>allow the MMC to drain its charge so by the time you get to it, the cap
>>won't zap you.
>>Each one of the 100 - .047 mF 1600 Seacor caps in mine have a 10 Mohm, 1/2W
>>carbon film resistor across them. Those resistors came from radioshack-dot-com
>>(on-line) and sell for 1 cent each in lots of 100.
>1-cent resistors are likely to be metal/carbon film, and may not have
>sufficient voltage rating (see recent discussions) - you want metal
>glaze if you have more than a couple of hundred voltas across a
>resistor. 
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