> -----Original Message-----
> From: Richard [mailto:2@mail.vcnet.com]
> Sent: 25 April 2002 04:01
> To: g0ruz@btinternet.com; AMPS
> Subject: Re: [Amps] homebrew glitch resistors
>
>
>
>
> >Is there any mileage in making a homebrew glitch resistor for
> use in series
> >with the B+ using Nicrome wire on a 1 inch diameter ceramic
> former. It seems
> >to me that it should be fairly easy to make one with the necessary
> >resistance,current and voltage breakdown characteristics.
> >
> >Has anyone done it? The commercial equivalents are really
> expensive here in
> >the UK and we seem to see very few surplus nowadays.
> >
> ? I would build one out of groved Delrin or ABS tubing and Ni-Cr
> resistance wire. 12' of #22 Ni-Cr should be about right.
> However, we buy glass-coated wire-wound resistors for glitch service and
> the price per 250 is just over $1US each. One 10-0hm, 10W unit will
> safely discharge c. 30uF @ c. 2900v. For higher V, we put more in
> series. For tetrode-with-handles glitch resistors, which need to be able
> to carry 4 to 6 amperes and discharge c. 2kJ of filter C, a real
> pulse-rated R would be better, despite the added cost.
> >
> cheers, Conrad
>
Hi Rich yes we have resistors like that here in the UK. They are 12watt
devices rated at 750 volts each and are made by Welwyn, its the low voltage
handling that worries me, the supply is 4.5kV with 25uf of smoothing, I
suppose 6 x 4R7 in series would fit the bill. They just look a little small
to me :-)
Conrad
|