Q&A Forum
Ok I connected V- from fan and stepper motor power supplies with yourdyno box. I see that after grounded all togheter i must reset load cell zero. Its norma?
I have also see that if a grounded the box, the noise on the load cell is higher. With grounded box is about 0.3/.4nm, without grounded 0.05/0.15nm. It is normal ?
Here what it does to me once its had a CDI ignition dirt track car on the dyno for 10mins.
https://youtu.be/8nHcYgYGCEc
And here is video comparing having bluebox earthed, not earthed, capacitor fitted.
https://youtu.be/7tCvtDWxX-Y
I see that also in your setup when you grounded the box the noise increases, Is correct ? What kind of capacitor do you have installed?
Eric,
Don't ground to the stepper power supply, it is likely noisy! If you need to ground the box, then ground it to a mains earth neutral point, or directly to a properly grounded structure.
The stepper driver has an optocoupler on the input, so don't let YourDyno share ground with the power supply in any way, you only need the 0V and OutA/B connected to the stepper inputs.
Ok but I have still noise on load cell and thermocouple. Load cell after calibration goes always up and down between - 0.30 and - 0.10Nm.
I see that also in your setup when you grounded the box the noise increases, Is correct ? What kind of capacitor do you have installed?
You can see what I tried when I went though issues here
https://yourdyno.com/community/questions-and-answers-questions-and-answers/noise-on-load-cell/
Ok, but is necessary ground yourdyno box? If is necessary, yourdyno box must be connect by wire at mains earth?
Because I still have noise on load cell and thermocouple. These noise disappears if I disconnect power supply.
It is not necessary to ground the box. If you have noise or emi issues, you may try that, but if you don't then don't ground it. If you ground it to a noisy source, then that makes everything worse.
Disconnect the arm to the pump from the load cell, see how much noise you get then. In our water brake we saw the hoses added load to the load cell and it varied quite a bit. 0.1-0.3Nm is very little. Put your finger on the load cell and you will see! Also, what size load cell do you have? Find out how much 0.1Nm or 0.3Nm is compared with the max Nm the setup can measure.
I think that noise is not caused by oil hoses. Sometimes the torque jump between 0.01 and 0.03Nm that is a good result, but usually, with power supply ON the torque (with engine off) jump about 0.2-0.3Nm.
This noise is the same between 50kg and 300kg load cell. I have buy shielded cable for stepper engine and capacitor (10uf ceramic) to connect in load cell wires if I dont solve this problem.
PS in my setup 0.2-0.3Nm isnt a big problem but I dont understand why sometimes this noise became very low.
So, in my case the communication loose got better with proper(more shielded) and shorter cables to load cells and rpm sensor
Hello...I have two pneumatic controllers working with Modbus protocol. When tested it in real time, i am getting data error at the slave side. It is assumed to be because of EMI. Anybody knows any method (or idea) to analyze the effect of EMI on this data error?