# current limiter using MOSFET

#### Skubby SkinnyChubby

Joined Jun 19, 2015
25
Hi all,

i want to create a current limiter circuit using MOSFET but i got no idea how to design,so can anyone guide/help me?

details:
24v input to the current limiter circuit and a 9A at the output to drive a load

thanks a lot

#### Skubby SkinnyChubby

Joined Jun 19, 2015
25
BUMP

#### crutschow

Joined Mar 14, 2008
25,269
Does the load need to be grounded?
What is the maximum load resistance?
What current accuracy/stability do you need?

Bump: My, you are impatient. 47 minutes is a rather short time to expect an answer.

#### Skubby SkinnyChubby

Joined Jun 19, 2015
25
Does the load need to be grounded?
What is the maximum load resistance?
What current accuracy/stability do you need?

Bump: My, you are impatient. 47 minutes is a rather short time to expect an answer.
what do you mean by current accuracy/stability?

sorry i'm very new to electronics

#### crutschow

Joined Mar 14, 2008
25,269
You said you want the current to be 9A.
Since no circuit can give a exact output it has to be designed to meet some tolerance on the current such as ±1ma, ±0.1A, ±1A, etc.
The tighter the tolerance the more complex and expensive the circuit required.

#### Skubby SkinnyChubby

Joined Jun 19, 2015
25
You said you want the current to be 9A.
Since no circuit can give a exact output it has to be designed to meet some tolerance on the current such as ±1ma, ±0.1A, ±1A, etc.
The tighter the tolerance the more complex and expensive the circuit required.

i only know the circuit will be connect to a DC motor and the expected output is 9A max.

this is all the information given to me..sorry

#### MikeML

Joined Oct 2, 2009
5,444
Begs the question? Why do you think you need to limit the current? A DC motor limits its own current (look up Back EMF).

Get a data sheet for the motor, and post it...
(without a data sheet, you are guessing, so is your boss, and more importantly, so are we...)

#### crutschow

Joined Mar 14, 2008
25,269
Are you trying to limit the motor startup current?

#### Skubby SkinnyChubby

Joined Jun 19, 2015
25

#### Papabravo

Joined Feb 24, 2006
14,252
If you put a hard limit on the current the motor might not start at all or accelerate very very very slowly. It is normal for the startup current to be four or five times the running current. If the 9 A. is a startup current, then what is the running current? Help us out and throw us a bone!