Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => AmpTools/Tech Tips => Topic started by: kagliostro on May 11, 2008, 04:44:52 pm

Title: Old Variac - seems 400 - 1200 Hz - can be used ??? New Question
Post by: kagliostro on May 11, 2008, 04:44:52 pm

Hi friends  :)

Iesterday in a little market I gor an old Variac

it was very bruised, not working and not clean

a 15 minute job, a little piece of abrasive paper, and now it is working

but cleaning it now I can read the nameplate and it seems is for 400  - 1200 Hz

May I use it (at 50Hz 220v) or is only a nice ornament ????

MANY THANKS for any suggestion

Kagliostro

Title: Re: Old Variac - seems 400 - 1200 Hz - may be used ???
Post by: FYL on May 11, 2008, 06:37:12 pm

Quote

May I use it (at 50Hz 220v) or is only a nice ornament ????

I wouldn't use it.

Title: Re: Old Variac - seems 400 - 1200 Hz - may be used ???
Post by: RicharD on May 11, 2008, 08:12:36 pm

Very odd.  I've seen ratings like that on meters but not a variac.  I'd set up a controlled experiment using incandescent lamps, a trusted volt meter and a trusted amp meter.  I'd bet it's OK, but my apprehension would be trusting something very old with supply voltage for amps on the bench.  The only thing worse than no test equipment is faulty test equipment.

Title: Re: Old Variac - seems 400 - 1200 Hz - may be used ???
Post by: FYL on May 12, 2008, 05:22:02 am

Quote

Very odd.  I've seen ratings like that on meters but not a variac.

Quite common in avionics, where "mains" is at 400 Hz.

Title: Re: Old Variac - seems 400 - 1200 Hz - may be used ???
Post by: RicharD on May 12, 2008, 11:17:15 am

Avionics..... well I change my reply to ornament then.  This explains the vintage meters I was pondering from Nebraska Sales.  I know nothing about avionics other than don't mess with the folks at the security check point.

Title: Re: Old Variac - seems 400 - 1200 Hz - may be used ???
Post by: PRR on May 17, 2008, 01:41:13 am

Rated input at 50hz will be 14.3V. Will probably stand 15V or 16V for many minutes.

Unless you have a need for low-voltage variable AC, there is not much use in it.

Title: Re: Old Variac - seems 400 - 1200 Hz - may be used ???
Post by: kagliostro on May 17, 2008, 06:09:24 pm

Hi  :)

MANY THANKS ( :'( :'( :'()

it will be better I use it as a nice ornament

Kagliostro

Title: Re: Old Variac - seems 400 - 1200 Hz - may be used ???
Post by: kagliostro on May 24, 2009, 04:50:41 pm

Hi

I resumed this old topic because I find this other topic

http://www.el34world.com/Forum/index.php?topic=811.0

can I thik to use my old 400Hz variac as in this PS ?

PRR told it can be use till near 14v

someone know how many current I can suck there ??

Thanks

Kagliostro