Current Sensor based on OpAmp

[mahmood]

Hi all

make your own current sensor for your Smps just with a singe opamp like LM358 .

note :

This circuit is just for maximom 30 Volt .

[golam]

Dear Mahmood,

Your schematic for current sensing in smps looks cumbersome to me. I use slow blow fuse at the input and fast blow fuse by little fuse or resettable fuse at the output side. These give very good result and saves the circuit because these react very fast and with resettable fuse, you don't require more than one fuse as one fuse will perform for few hundred times. So, over current protection of the circuit becomes easier and efficient.
Thanks.

[darkfenriz]

Is that intended for current mode operation or short circuit protection? Any good source of 10 miliohm resistors?

[mahmood]

Hi

for short circuit protection may good . in EWB it responsed so fast
you can add it to a SG3525 shut down pin of course with two
opto coupler and simple circuit like to relay insted LED .

[mflorin]

check the link. It could give you a better understanding...
http://focus.tij.co.jp/jp/lit/an/sloa044/sloa044.pdf