Short circuit protection

[curious]

I have a 40-90V DC input driving some logic circuit.I am trying to protect the circuit by turning it off above 3 amps.I have checked some polyswitch fuses(have not found anything matching my requirement).I am also looking to implement it using a current sensor.I do not know how to proceed beyond this point , can anyone pls help.

 

[JimB]

More information required.

What is the "logic circuit"?
Why the high voltage?
Does the "logic circuit" normally draw 3 amps? Sounds rather a lot.

JimB

 

[Russlk]

Will a current limit work? Or do you want to shut down at 3 amps? Is there other low voltage available?

 

[curious]

The logic circuit has some mosfets driving a relay with pwm output.
The load current is 2.5 Amps ( maximum of 3 amps)

Any current limiter will do cutting off at 3 amps.There are no other low voltages.It is a little urgent Pls help.

 

[Nigel Goodwin]

I suggest you post the circuit of what you have, your request still doesn't make any real sense?.

 

[Russlk]

Try putting this circuit in the return line. The IRF630 will get real hot when it current limits.