Posted by: eric91

Hi, has anyone had EMI problems with thermocouple? Has anyone solved this problem and how?

Thanks

Eric

Hi Eric , have you worked out what is causing the  electromagnic noise in the vircinity of your thermocoupling wiring acting as a antenna ?

Possible causes of the top of my head!

1. Stepper motor ?

2. AC power supply ?

3. Engine ignition system ?

4. Thermocouple lead way to long and looped ?

5. And any other electrical devices? Even a mobile telephone?

Have a look how coaxial cable is made and maybe model something similar for your application to shield the cable totally. 

Sorry i couldn't help anymore.

Eric, can you send me a raw log, let me take a look.

I still have problem with thc measurement. I have try with shelded cable and nothing to do, I also have try to grounded thc with resistance but still not working. The problem appears also with off engine and with off electric power supplies. 

Posted by: eric91

I still have problem with thc measurement. I have try with shelded cable and nothing to do, I also have try to grounded thc with resistance but still not working. The problem appears also with off engine and with off electric power supplies. 

AREA specific !!!  take the temp  sensor and amplifier away from the area you're in testing , if the problem is there still , you may have a faulty unit?

Would drive anyone insane !

Sorry but I dont understand well what do you mean, could you explain yourself better?

Thanks

Posted by: eric91

Sorry but I dont understand well what do you mean, could you explain yourself better?

Thanks

 

Take box and laptop some where outside Dyno room. If still has noise then it's the box.

Ok, I have try in to dinner room away from EMI sorhents and the results are the same. Thc Channel seems not working, also with shelded cable and also with other 2 thermocouples. See the video attach here. 

Try unplugging the power cord from laptop so its running battery only.

Strike, with unplugged power cord it work pretty weel. I will try in dyno room with engine and I will let you know. 

Noisey power supply.
Came across that issue when trying to sort the noise I had on load cell.
Im running dyno PC off a UPS which helped a lot. And then a CAP to filter that last little bit.

And also a tip for tuning is you should never run the laptop off mains while its connected to the car in anyway because its puts noise though the whole car.

Please could you explain me more easly ? Sorry but my English isn't very good.

Thanks a lot

What do you want explianed?

From memory you're running a hydraulic pump hooked up to a single cylinder engine ? So I'm making an assumption you a small dyno room ( cell ) housing all your goodies inside. That why l said test the temperature sensor/amplifier away from all power supplies. 

Totally forgot about you laptop/pc if it is in very close proximity. 

Possible causes of the top of my head!

1. Stepper motor ?

2. AC power supply ?

3. Engine ignition system ?

4. Thermocouple lead way to long and looped ?

5. And any other electrical devices? Even a mobile telephone

 

A UPS ( Uninterrupted Power Supply) is a battery back or use as a battery power supply like BMGJet said eliminating a switching power supply.

Hows the EMI noise now?