Re: NST protection circuit

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

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Parpp807-at-aol-dot-com>

In a message dated 4/22/01 3:04:08 PM Central Daylight Time, tesla-at-pupman-dot-com 
writes:

<< I have used smaller ones of these before and due to there anodized aluminum
 casing that acts as a heatsink, the heat issue is drastically reduced. In
 addition to helping with the heat, the case also makes the resistor look very
 presentable:). >>

Will,
The heat is produced as an I squared R loss (also P=EI) and bears no 
relationship to the physical distance from the NST. If you connect the 
resistors in series the current will be the same thru each resistor.  The 
power rating of the resistor is the Wattage that may 
be safely dissipated by the unit of that particular physical size and design. 
I would not use 
metallized resistors anywhere near the high voltages of a NST. Suggest you 
use the Ohmite vitreous enamel power resistors. The 100 W resistors used in 
Terry's NST protection circuit are deliberately chosen for their quality and 
wide safety margin.
Also, The aluminum casing of the resistor is just cost cutting design. It is 
not a heat sink
unless you mount the resistor so it is in contact with something that will 
soak up (sink)
the heat.

Hope this helps.
Cheers,
Ralph Zekelman