I'm looking for a way to limit the current through the mosfet in the circuit provided. I'm hoping to limit the current through the mosfet to about 10 amps.
I'd also like to keep the number of components to a minimum because space is limited.
Thanks in advance for your help

 

Can the load stand to have a 60 milliohm current shunt resistor between its neg connection and ground? This will decrease the output voltage seen by the load by 0.6 V at 10 A.

If yes:
1 - additional MMBT3904
1 - 0.060 ohm resistor

This will have a "soft" current limiting knee. That is, you will not get full voltage up to 9.99 A and hard current limiting at 10.00 A. The output voltage will start to sag at around 8 A and drop to 0 V at 10 A. ish. Figure +/-10% for this most simple circuit.

The next layer up in complexity adds an adjustment pot and increases the 10 A voltage drop to around 0.8 V. There still is a soft V-I curve knee, but you can adjust out some of the circuit tolerances. Because the trip point still is dependent only on the transistor Vbe, it will drift with temperature.

ak

 

Below is the LTspice simulation of your circuit with a simple added current-limit circuit.
The current limit is approximately 0.7V / R1.
I also modified the input transistor circuit to get proper bias to the MOSFET for both 12V and 24V power.

As AK noted, the current limit is temperature sensitive due to the change in Q1's Vbe with temperature. The variation is about -0.23%/°C.

(Note that you show the P-MOSFET upside down in your diagram.)



Edit: Below is the simulation with the load resistance varying from 0.1Ω to 10Ω, showing that the limit is fairly stiff with change in load resistance.

 

I misread the MOSFET in post #1 - I thought it was an n-channel in a source follower configuration because of the drain connection to Vcc, hence the NPN current sense transistor. As noted, Wally's circuit fixes that.

ak

 

Note that the MOSFET dissipation can get quite high if you have a low resistance load, since its dissipation is (Vpwr - Vout) x 10A.
For a short circuit with a 24V power supply, that would be 240W, which would likely zap the MOSFET, even if it's on a heatsink.