Hello,

Can anyone help me this question?
What fomulars to find out the AC input current when increasing AC load at AC output of power transformer?
If we can determine the input current by the fomulars, then I don't need to cut the wire insulation to measure the input current on the input hot wire.

Thanks in advance.

ken

 

Since it's ac wouldn't it be easier to use a clamp on ammeter?
You wouldn't have to cut any wiring.

 

It's basically watts in = watts out x [(efficiency in %)/K] but you can usually figure it as

watts in = watts out as a rough estimation, at least close enough for most calculations.

To really get the rest of it becomes quite complicated due to the core, wire sizes and the way it's wound.