Buck converter output current prediction

[dougcooper]

Greetings all

I am trying to find a method to determine the output current of a buck converter without knowing the load (but assuming that it is resistive) or interfering with the circuit by adding a sense resistor or current transformer (so I'm restricted to voltage measurements). My idea would be to measure the output voltage accurately enough to be able to see the switching frequency and duty cycle and use these along with an averaged model of the converter to calculate current. Unfortunately this has not produced accurate predictions in simulations or physical testing. Any advice or pointers would be greatly appreciated.

Best regards
Doug Cooper

 

[mtwieg]

No, voltage measurement alone isn't enough to derive current if you don't know impedance. Can't you use a hall effect sensor to measure current directly?