Amperage Control

[PsychoMaster]

Hello All
Just starting out and making my own PSU I am now at the stage of amperage control and really don,t like the look of a LM317/338 and a resistor to control  current. It,s down to the  inflexibility of finding a suitable bank of resistors to change the current value. After seeing Dave's current load device I was thinking could  the resistor be replaced with a mosfet as in Dave's circuit.Would this not handle the current and also the resistance values?I wanted to use analog devices to reduce noise in the output as I am not sure about switch mode signals.
Cheers

[Paul Price]

Instead of trying to waste heat using a large-valued sense resistor, use a tiny resistor to sense current and amplify the result to feedback to the voltage control so that current can be limited by reducing the voltage to the set current you desire.

Take a look at the schematic below. It uses easy to find, off-the-shelf components.

[PsychoMaster]

Cheers mate I will have a go at this one ,I am now using six lm388 in parallel that I was going to drive with a op amp and I,ll adapt this into the circuit.I am only going for 5 amps so the six lm388s should have a easy time of it.