im trying to make a control valve using thermocouple and a stepper motor (which is connected using TB660 motor driver), at first it all worked out fine when arduino, thermocouple, and PUL+ ENA+, are being powered by my computer's power (5V) and my stepper is being powered by a 12v 3A power supply.
once i try to put these circuits on to an aluminum plate (which is the place where the circuit are going to be permanently placed) and using a 24V 20A power supply, while my arduino and thermocouple are being powered by 12V 5A power supply, the thermocouple's reading falls down to zero. but the weird part is when i turn off my 24V power supply, the readings comes back to 28, which is the real room temp. in both condition when i heated up the thermocouple, the numbers would still go up but with an offset of 20C. eg. when i was not connecting the 24V power supply, the readings would reach 100C, but when i connect the 24V, the readings would go down to 80C and it would also oscilate a little.
im suspecting that the thermocouple is receiving less amperage as the motor driver (which connects to the 24v power supply) is turned on. sadly my multimeter broke and cant measure the amount of amps that is being drawn by both instrument.
is there any posibble solutions to this ? are there posibbly a short circuit going on ? i have been trying to ground the power supply, and the GND pin from the arduino, but to no avail. i've tried to rewire the PUL- and DIR- to the 5V of the arduino but still having the same result
Can you express "incredibly hot." in degrees C?
We need a wiring diagram or schematic, can't tell anything from the fuzzy picture.
Also, out of the thousands of different stepper motors, which one do you have?
the temp gets to the point where i cannot touch them, and for the wiring diagram, i used the common anode wiring for the motor driver. i used NEMA23 stepper, but i dont know it's manufacturer since i got this motor from someone else, and there's no data plate for the motor
here's more or less the wiring diagram for each of my motor driver. i've tried to check and reconnect the wires over and over again and still no result
i have make sure that my thermocople is not connected to anything conductive. yes i have grounded them to the common ground but i havent tried to also ground the GND pin of the arduino, is that necessary ?
i am using the common anode wiring, so more or less the wiring looks like the one that i have answered to the ones above. unfortunately i dont have the spesific specs for my stepper, but im currently uusing NEMA23 motor drived by TB6600 , and using type K thermocouple connected to max6675
i hope this helps, i have tried to do the schematic as best as i can.
yes the TB6600 does set current limit at 3 amps. but unfortunately i cant really describe my stepper's spec other than saying that's its a NEMA23 stepper since there's no data plate on the motor sorry
Sorry but can I suggest you sit down with pen(cil) and paper and draw your circuit, include component names and pin labels.
(It will be quicker and you have a greater component library to draw from.. pun intended )
It might look daunting but to properly troubleshoot your project we need an accurate diagram.
What are your two PSUs, link to spec/data please.
Do you have a DMM? (Digital MultiMeter)
Something like this would be clearer: (I use CAD cos my neuropathy does not draw very well.)
HI Tom,
thank you so much for the response, i really appreciate it
from that picture of yours, isn't that just going to short the 24V transmision ? im sorry for being such a noob here, the resistance is about 1.1 ohm for each coils while the motors are off. yes i did have them grounded as well as my plate where all the parts are sticked on to. i have my psu grounded from the pins that thhey are provided, are these steps correct ?
by the way i have found my problem. it seems like my systems is having a current leakage. that i dont know the source yet. and i found this out by having my thermocouple's shield grounded. it finally could increase the readings of the thermocouple. hopefully i could find the source of this leakage.
but sadly this doesn't solve my hot motor's problem. since the current still probably goes into my motor and somehow increase the current each of my stepper's coil. to give you the perspective of how hot the motor is, it would get to the pint which it could burnt my hand when i leave it running for such a long time.
both of them are being powered by my 12V Transmision. and each of them would control one stepper motor, but in the future i would add another stepper for the Mega to control
by the way, adding capacitor to the plus and minus connection of the thermocouples on the max6675 did the work. the size of the capacitor didn't really matter
