Swend
Full Member level 4
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Hi friends,
I understand there are three ways of calculating power
(UI) P = U * I
(UUR) P = U² / R
(IIR) P = I² * R
When I measure voltage, current and resistance in my circuit, and plug the values into the above formulas - I get three very different results. So the question is which one is correct?
(UI) P = 809.471 W
(UUR) P = 25W
(IIR) P = -3.731 W
All above are average power.
This is my circuit
This is the voltage and current measurements. The resistance is 1M ohm both nominal and measured with a DMM. I also checked the voltage divider, it has a flat frequency response up to about 20MHz.
And this is the calculated instantaneous power using the above three formulas.
I understand there are three ways of calculating power
(UI) P = U * I
(UUR) P = U² / R
(IIR) P = I² * R
When I measure voltage, current and resistance in my circuit, and plug the values into the above formulas - I get three very different results. So the question is which one is correct?
(UI) P = 809.471 W
(UUR) P = 25W
(IIR) P = -3.731 W
All above are average power.
This is my circuit
This is the voltage and current measurements. The resistance is 1M ohm both nominal and measured with a DMM. I also checked the voltage divider, it has a flat frequency response up to about 20MHz.
And this is the calculated instantaneous power using the above three formulas.