[Amps] Glitch Resistor

[Ian White GM3SEK]

Bob Maser wrote:
>I'm having a hard time finding a 50 ohm 50W resistor for a glitch 
>resistor for my 4CX1500B amp.  Seems I remember that I could also use 
>some AWG 30 for
>a glitch.

If they mean to use it as a fuse instead  of a resistor, then NO.

A fuse provides no current limiting until *after* it has blown. In the 
time it takes for a fuse to blow (which depends on the size of the 
current surge) an arc from B+ can do a lot of damage.

That is why Eimac recommends a resistor, to provide truly instantaneous 
current limiting. The resistor is there to buy time so that some other, 
slower device like a fuse or breaker can shut the HV supply down safely. 
The resistor also guarantees an absolute maximum level of surge current, 
that the rest  of the circuit can be designed to tolerate.

See the copy of Eimac Application Bulletin 17:
http://www.ifwtech.co.uk/g3sek/misc/bull17.pdf




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73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek