[AMRadio] Transformer help

[Gary Schafer]

wwd at netheaven.com wrote:

> Gary Schafer <gschafer at mediaone.net> said:
>
> >Thanks for the response Bill. What I was trying to find out was if the
> >particular transformer was rated  220 or 120 volts. It has no markings
> >and only a single wound primary. I did find out how to check. By applying
> >voltage with a variac
>
> That was hoped for, or at least that a fuse/circuit breaker of some sort
> would be used.  My feeling was that any hypersil core xfmr is probably
> good for 240vac- anyone ever seen one that wasn't?
>
> A 25/40/100 watt bulb in series with the variac and primary will give an
> indication of current flow increase if you approach any 'trouble zone'
> while cranking up the variac. Only a voltmeter across secondary during
> this test, of course.
>
> That primaries normally operate within 20% of overload point seems
> rational. A wider margin would not be cost effective.
>
> So you still haven't put 240 across that primary??  <g>
>
> Bill        N2KQA
>
> >73
> >Gary  K4FMX
>

O yes I did put 240 volts on it. Started out with a 110 volt variac across 1/2
the 240 line. Had a clamp on ammeter on one leg. Got it cranked up to about
270 volts or so and did not see much of a reading on the 6 amp (lowest scale)
on the clamp on ammeter. Then put the dvm in series with a leg on ac
milliamps. Got a reading of a little over 200 ma at around 240 volts.  So.. I
am assuming that the transformer has a 240 volt primary.
But are you saying that all 120 volt hypersil transformers will operate on 240
volts without any problems ?

73
Gary  K4FMX