>
>Gee, Mercury vapor is a metal vapor isn't it? Is that what is in most
>Thyratrons?
>Or maybe Hydrogen in some which has the same properties of metals when
>ionized.
> VOA 's Collins transmitters used an air arc gap for their crowbar. It
>consisted of 2 brass balls (one to B+ and other to B-)
>and a needle between connected to a big ignition coil. When the vapor phase
>cooled finals arced a spark would appear between
>the needle and the balls and dump the power supply's energy. The Crosleys
>used Thyratrons.
>What got me thinking about this method of protection was some exploding
>wires experiments.
> I'd rather sacrifice a resistor over a tube any day.
>
If the glitch R can not withstand the dreaded "screwdriver test", a more
substantial glitch R is needed.
cheers, Bill
>
>
>
>
>At 10:40 AM 11/28/00 -0800, you wrote:
>> >
>> >I was thinking that perhaps a simpler approach would be to have a glitch
>> >resistor of low wattage (in B+ line) such that if you had an arc over in
>> >the tube the resistor would quickly self destruct.
>>
>>The metal vapour arc of an exploding resistor is unlikely to limit peak
>>fault current.
>>
>> >placed inside of a well grounded copper pipe the plasma produced would
>> >almost instantly dump the B+ straight to ground. Obviously you would have
>> >to replace the resistor but perhaps it would save the expensive power tube.
>>
>>not necessarily
>>
>> >The copper pipe would also catch most of the resistors shrapnel as well. HI
>> >HI HI
>> > What do you think?
>> >
>>I would select a resistor that could withstand the fault current without
>>damage.
>>
>>end
>>
>>- Rich..., 805.386.3734, www.vcnet.com/measures.
>>end
>
>
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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