current detector + led flasher

[carmusic]

Hi i need to build a current detector using a small shunt resistor on the low side, and if there is current flowing i need to light a led, when there is no current the same led flash.
I was thinking building it using la low offset amplifier (mc33272) to detect very small signal on the shunt (les than 1mv) and configure it as a high gain. for the flasher i would take the second amplifier. and then i needed two diode to combine together the light up the led, but that takes a lot of resistors.
how would you build it? Pricing and number of parts is very important i will have to solder all those parts for high volume production.

It works on simulation but if is there a better way to do it?

 

[audioguru]

Some of the opamps will have a 1mV input offset voltage then the output will be plus or minus 13.6V without any input signal. You will need an input offset voltage null trimpot.
If it is powered from a battery then a supply bypass capacitor is needed.

 

[carmusic]

that why i will use a 0.1mv max offset op-amp

 

[audioguru]

An MC33272 has a max input offset voltage of 1mV.
If you use another opamp with only 0.1mV of input offset voltage then some of them will have an output voltage of plus or minus 1.36V in your circuit without an input signal.

 

[carmusic]

Ok i may lower the gain then