[ARC5] Filament Power Sources

[Ian Wilson]

I have blown a filament on a 4-125A when using a PC power supply. While
a single case doesn't prove anything, this has never happened when using
a transformer for filament power.

I wonder whether the inductance of a real transformer acts to limit the
starting transient, whereas a switching PSU is much stiffer and might stress
a brittle filament on switchon. I am told that PC PSUs can be made somewhat
soft-starting by adding a capacitor across the reference voltage resistor,
but
haven't tried it.

73, ian K3IMW



On Sat, Aug 24, 2013 at 5:35 PM, Robert Eleazer <releazer at earthlink.net>wrote:

> If you needed a lot of filament power at 6V, would there be anything wrong
> with adjusting a 5VDC power supply up to 6V?  I have one of those that will
> adjust up to 6V via a pot control and it'll put out 100 amps.
>
> Wayne
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