More accurately up to it's rated wattage "Power = Voltage * Current" after all.

If you have a 100W max variac you can draw 20A @ 5V (approx) but only 1A at 100V.

On 12/8/2021 4:44 PM, Mike Katz via cctalk wrote:
"As a general rule, a variable transformer (Variac) can provide full rated current at any output voltage. So a 2.5A unit can provide 2.5 A at 1V, 10V, 120V, etc. With a 20V output, that is 50 VA (Watts, sort of)."

Up to the current rating of the variac.  When you draw more current than the transformer can deliver then the voltage will sag.

On 12/8/2021 4:22 PM, Will Cooke via cctalk wrote:

On 12/08/2021 3:58 PM Rob Jarratt via cctalk <cctalk@classiccmp.org> wrote: So, to supply the bricks on the bench, would a variac rated at 2.5A be OK? I am not sure I know how much current the bricks will draw at 20VAC, and at what voltage the 2.5A rating is given. Otherwise, would this do the trick? https://cpc.farnell.com/block/steu250-48/transformer-250va-230-400v-2-x/dp/TF01418?st=24v%20transformer

Thanks

Rob


JRJ
As a general rule, a variable transformer (Variac) can provide full rated current at any output voltage.  So a 2.5A unit can provide 2.5 A at 1V, 10V, 120V, etc.  With a 20V output, that is 50 VA (Watts, sort of).

Will

"I was born not knowing and have had only a little time to change that here and there."
Richard Feynman


Reply via email to