Fixed current power supply 100A DC

[nametc3]

I need design a fixed current power supply DC 100A, about 200W, help me thank you !

 

[audioguru2]

What are you going to use 2V at 100A for?

 

[nametc3]

I want measure resistance about micro ohm, by mV metter drop on resistance

 

[ante1]

You could rewind the secondary 5Volts (or 3.3V) in a computer PSU to 2Volts (or which voltage you want) and boost the rectifier circuit. You have to arrange a shunt and some feedback to the regulator circuit to obtain a constant current.
There are different ways to do this but these are heavier and more expensive.

 

[indulis]

But 1 micro ohm and 100A gives you .1mV. You said you have a mV meter.


Seems like a better meter would be an "easier road", than the cost and trouble of constructing a 100A source (these current levels are not easy to deal with). Contact resistance and wire IR drop come into consideration REALLY FAST!!

 

[ante1]

Hi indulis,

I agree, 100A is not easy to handle and there might be a better solution to this depending on the target for the measurements. This amount of current will sure require some heavy duty KELVIN CLIPS!  ;D

 

[Muhammad Abu Bakar]

Hello nametc3,


To measure R in uOhm range KELVIN bridge is used. It uses meter movement (as your v-meter) to detect the test resistense arainst a variable known R.

If u plan I-surce V-meter then even the connecting wires can add up to many more u-ohms. Its not practical approach at this level of R.

Search www for more on Kelvin Bridge.

 

[nametc3]

thank
But I want have diagram source fixed current 100A DC, help me