Inductor Current Shunt

[Alexsgarage]

I am building a power supply and I need to include an overcurrent detector. Peak current through the supply should not exceed 13 amps, I was thinking that I could use a shunt resistor and a comparator on the DC side of things but I dont have any good shunt resistors in that power range. I then thought of using an inductor on the AC side of the supply, an inductor in series with the 120V 60Hz AC input will have a given reactance and may act as a resistor of a given impedance, I was wondering if this will work as an AC current shunt.

 

[smanches]

Why not use the inductor on the output? You could create a low-pass filter with the output caps to help smooth things out, and also use it as a current sense resistor.

 

[crutschow]

How about a length of iron or nichrome wire as a shunt resistor? Iron has about 50 times the resistance of copper and nichrome has about 600 times the resistance.

 

[BrownOut]

I am building a power supply and I need to include an overcurrent detector. Peak current through the supply should not exceed 13 amps, I was thinking that I could use a shunt resistor and a comparator on the DC side of things but I dont have any good shunt resistors in that power range. I then thought of using an inductor on the AC side of the supply, an inductor in series with the 120V 60Hz AC input will have a given reactance and may act as a resistor of a given impedance, I was wondering if this will work as an AC current shunt.

Go with your first idea. You should be able to find a suitable resistor. If not, you can kuludge out together. I don't like the idea of an inductor, either on the input or output sides.