In article <UEnPj.340884$DR7.326391@[EMAIL PROTECTED]
>,
"Iain Churches" <IainNG@[EMAIL PROTECTED]
> wrote:
> "John Byrns" <byrnsj@[EMAIL PROTECTED]
> wrote in message
> news:byrnsj-1CFED7.09332022042008@[EMAIL PROTECTED]
> > In article <etmPj.340844$A97.323045@[EMAIL PROTECTED]
>,
> > "Iain Churches" <IainNG@[EMAIL PROTECTED]
> wrote:
> >
> >> "John Byrns" <byrnsj@[EMAIL PROTECTED]
> wrote in message
> >> news:byrnsj-D6B303.08411522042008@[EMAIL PROTECTED]
> >> > In article <824Pj.340419$G71.82199@[EMAIL PROTECTED]
>,
> >> > "Iain Churches" <IainNG@[EMAIL PROTECTED]
> wrote:
> >> >
> >> >> Can I suggest a topic for you? A current limiter for tube
heaters.
> >> >> People are keen to use voltage regulation, which doesn't seem to
> >> >> me to be so important. Heaters are specified at +/- 5% so
> >> >> anything between 6V and 6V6 for a 6V3 heater is within tolerance,
> >> >> and with a wirewound pot between two 'lytics one can get it spot
on.
> >> >> But heaters draw huge currents at switch on. Do you have a
circuit,
> >> >> using those funny black things with shiny legs, that could current
> >> >> limit? Two circuits would be of interest. One at say 1.2A
> >> >> (a pair of B9A's) and one at 3A (a pair of EL34's)
> >
> > I forgot to ask, what is a "B9A", I can't find a listing for this tube
> > type?
>
> It's the tube base designator for a miniature 9 pin, 12AU7 etc etc.
Yes, that's the only meaning I could come up with, but I discarded it
because it didn't make particular sense in the context of a 1.2A current
rating, I guess I should try to find out what "B9A" tubes you favor in
your designs.
Regards,
John Byrns
--
Surf my web pages at, http://fmamradios.com/
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