[PIC] Interfacing PIC24FJ128GC006 microcontroller with Shunt

Hi Klaus,
The output of the differential Amplifier circuit I used is not consistent i.e the output is +/- 25mv with constant load which is too high. Is that possible to reduce this error.

Thanking You,
Ravi.

Hi,

without the requested information it is impossible to help in your details.

Klaus

Hi,

I am trying to measure current across the shunt by measuring the Voltage drop across the shunt. As mentioned above 75 milli Volt is observed across shunt when 500 Amps current is applied. Current from 0 Amps to 10000 Amps will be passed through the shunt at times and the load is switched ON for 0.5 seconds only. So 10000 Amps shunt voltage will be 1.5 Volts.

I couldn't find any proper signal in Oscilloscope, Display is covered with noise. But I am reading the Shunt voltage perfectly with the circuit I used when load is connected for a minimum period of 1.5 Seconds with 10% error and error can be adjusted later. How to minimize noise from the circuit.

I have interfaced the circuit with dsPIC30F5011, One of my colleague says that this problem will be solved when we interface the circuit with PIC24FJ128GC006 as it is having good advantages in ADC convertions like 10 Msps, Hardware multiplexed integer conversions for multiplications and divisions....will this really help us.

Thanking You,
Ravi.

Hi,

Before there were 500Amps, now 10.000 Amps.
With a huge 15.000W of power disspation.

You never shwod the requested wiring diaigram, nor a waveform, nor a scope picture, nor a photo of your circuit.
And now you increased current by a factor of 20.

Your textual descripion is confusing me. One time the load is ON for 0.5s and another time it is 1.5s.
Scope signal is noisy, but voltage reading is perfectly...How is your voltage reading? Scope? DVM?

How to minimize noise? We don´t know how your noise looks like....and where it comes from...

10MSps will help if you need to know high frequency response of your signal, but it can´t avoid noise.

*****
Measuring 10000A usually is not done with a shunt. There are current transducers...Wit output signal isolated from power path.

Klaus

Hi,
Shunt output is 75 Milli Volt at 500 Amps and its output is proportional with current upto 10000 Amps. So at 10,000 Amps the potential voltage across shunt terminal would be 1.5 Volt.

The load is switched ON for a period of 0.5 Seconds only during real time application, and now for testing we have load up to 2000 Amps on which we have tested. We were able to sense with 10% error which could be fixed later and we were able to sense when the load is switched ON for a minimum period of 1.5 seconds, when we try to sense during 0.5 seconds our error is 30%.
I will upload the oscilloscope images shortly, even we are in confused to see output with 10% error when the hardware is filled with noise.

Thanking you,
Ravi.

Hi,

We were able to sense

Click to expand...

....Again i have to ask: How do you sense this?
DVM or scope or ADC?

Klaus