On 8/8/05 8:28 AM, in article ,
"Panzer240" wrote:

"Diane" wrote in
:

Dumb question, but how does it affect my old tube receivers slowly
bringing up the voltage using my 12amp variable transformer versus a
smaller one? Is it just overkill or is there some danger to the radio?
-Phil (not Diane)



As stated no effect, excpet in the case where you try to use it with
something that requires more than 12 Amps of current. Then you will get smoke
from the Variac How much smoke depends on:

1. How fast your reflexes are and:
2. How much more current than 12 amps the device requires.

:-D

I'm jumping into this thread late, but....

Actually, there is one other condition which requires caution.

Your "Variac" may be capable, depending on the model and options that are
wired, of putting out a stepped-up voltage. As I recall, mine can raise the
voltage about 15%. It's a useful option, but you must be careful, and don't
use it until you have a need you clearly understand.

As to the 12A limit; 12A is a bunch of current, but equipment uses only as
much as it needs. You can fairly accurately determine the current your
receiver should draw by checking the receiver specs for the Watts. Often
this will be on a label on the rear or bottom of the receiver.

If your nominal line voltage (E) is 120V and the posted Watts (P) for the
receiver is 350, then the current (I) should be 2.92 Amps (I=P/E).

Don



Don