[General] Need to measure 0 to 100 amps DC using MCU

hi

I need to measure safely 0-100 amps DC which is easily available , for inverter project using micro controller ADC with-in the scales 0-5 volt dc.

some surge more than 100 amps is expected that time controller needs to be in safe ADC voltage .

I am not much familiar with op-amps :sad:

I am not much familiar with op-amps

Click to expand...

Also you are not familiar with Wiki? It looks like you did not do a previous search.

andre_teprom said:

It looks like you did not do a previous search.

Click to expand...

Many are not suitable to handle surge currents ,and mostly i would like to prefer Hall effect sensors as its needs a little calibration and not effected by environmental factors,But most of sensors are not available in my market.

You have not mentioned previously if you wanted an electrical insulation and so the assumption that a simple shunt in parallel with a resistor voltage divider along with an operational amplifier in a non inverting topology could suffice. Unless you are dealing with very high frequencies, any rail to rail OpAmp with low input offset could do the job.

Hi,

If non-isolated is an option, why not use a current shunt monitor with programmable gain? They are easy (like everything in electronics, "easy" is relative but these are truly simple) to implement, they use Kelvin sensing, you can select one for the output range to fit the ADC used and you can include some margin for surges. They must be available everywhere, they are such a common part.

The BigBoss person here posted a great little Hall effect (so isolated) current shunt monitor IC a few months ago as a suggestion to a current-measuring thread, maybe Allegro make it..., I just looked and can't find the datasheet online because I do not know the part number by memory - sorry. Maybe someone else here on the forum will remember the device I mean.

If using a shunt there are many purpose build 'current shunt amplifiers' with fixed gains such as 20X or 100X. Some of them also include the shunt for convenience. Just one example (the 'INA' line from TI has many others):
https://www.ti.com/lit/ds/symlink/ina202.pdf

This is an Allegro IC type hall effect sensor (isolated) d123 was mentioning. This type of sensor is very small and inexpensive but less accurate than the larger 'closed loop' types (and more susceptible to magnetic fields, but still good enough for many applications).

**broken link removed**

hi all,

ACS770 is not available in my local market , ACS712 is available but it can measure upto 30 Amps only, now only option is to go head with type INA202 but its SMD , is there any similar available in DIP package or there is any chance this could be done with LM358 or any other better one ?

NIDHINDAS said:

ACS770 is not available in my local market , ACS712 is available

Click to expand...

The ACS712 is outdated, manufacturer recommends to use the ACS723 instead.