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Re: 4.5amp Variac good enough?
Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>
A 12000volt 30mA transformer can be rated in "VoltAmps" or "VA" which is the
measure used for such things. You simply multiply the voltage and current. so
your transformer is:
12000 x 0.030 = 360 VA
Your variac is the same idea so:
120 x 4.5 = 540 VA
So the variac has plenty of room to spare. You will want about 90uF for a PFC
cap. However, from the chart below, your tranny would run about 550 VA without
a PFC cap so you would still be close to fine.
You may note that variacs can be run at higher than recomended power too for a
short time as shown in figure "F" below. A little fan helps a bunch too.
However, it is always best to run things within their ratings if you can...
At 09:14 PM 2/25/2001 -0500, you wrote:
> Hi,I have a 4.5amp variac and wondered if a PFC capacitor used with a
> 12kv30ma NST could be fed by the 4.5amp variac?