[atommat]

in reply to: Where can I find an osPID online? #4091

i have an osPID (its the nuts!!)
this is my feature wish list…

1. BLUETOOTH!!
2. AC power
3. some way to mount the face in a project box.
4. multiple thermocouple type selection. ie..k, R, S or what ever.
5. a more friendly way to create profiles
6. (this may already exists) a way to specify temp climb per hour ie. 100c per hour until 1000c
7. finally, some way to output/log input and output to file

mat

[atommat]

in reply to: Thermocouple grounding #3979

just to keep this thread alive, because its important….

Ive had significant problems with the osPID. ive been using a kiln thermocouple that wasnt grounded and the readings have been zeroing out erratically when i hit ~900c. Ive been informed again and again that grounding is the issue. Ive no real idea what this means, im no electrical engineer but I switched to a thermocouple that was shielded (the shielding was then earthed) and BINGO…. back in business.

My other PID from Auberins is reportedly compatible with grounded and ungrounded thermocouples. I can therefore deduce that the osPID is only compatible with grounded thermocouples. Unless someone can explain how to make the osPID compatible with UNgrounded thermocouples then you should stay clear of them.

heres the proof….

[attachment=0:q7vofqjh]Screen Shot 2014-02-03 at 18.45.51.png[/attachment:q7vofqjh]

mat

[atommat]

in reply to: Wierd Input error and hard to get no overshoot. #3966

yes ive tried several power supplies, all with same issue. My other PID seems to be quite happy with the setup. I know what youre thinking…why not just use the other pid!? but its a mystery id like to solve. : )

[atommat]

in reply to: Wierd Input error and hard to get no overshoot. #3964

The thermocouple is isolated by ceramic shielding and is then extended through insulated thermocouple wiring all the way through to the osPID contacts. There is zero metallic contact between the thermocouple and the system. I did try earthing the thermocouple to see what happens but this just zeros out the readings. Can you think of any other potential problems?

btw, I do have another PID that works perfectly when swapped out with the osPID.

The mystery continues

[atommat]

in reply to: Wierd Input error and hard to get no overshoot. #3962

just to conclude my findings.

setup:

hobbycraft 13A kiln
High Temperature Thermocouple for Kiln (TC-K-KLN), Auberins
osPID with 12v 2A DC supply
25A SSR
Macbbok Pro w/wo charger

symptom:
repeating input errors both in the Frontend and without. when the temperature reaches 900˙c ac chargers and ac USB begin causing errors. at 1000˙c all PSUs cause errors at 1050˙c all battery DC/usb causes errors. ALL ERRORS AT ANY TEMP ARE REMEDIED SIMPLY BY DISCONNECTING POWER TO THE KILN.

precautions undertaken
– all ac and dc are supplied on seperate circuits.
– physical position of thermocouples have been isolated from ac
– attempted to ground thermocouple but failed to prevent errors.
– 3 seperate shielded and unshielded TCs tested

assumptions
– significant ac noise from power supplies is affecting the thermocouples.

cant explain
– why the higher temperatures cause more pronounced erroring.
– why a dc battery without ac psu can affect the error the way it does.
– why the removal of AC from the kiln remedies the entire erroring issue

what next:
i have another PID and will be using this until i can establish a fix.

sorry osPID… i tried everything 🙁

mat

[atommat]

in reply to: Wierd Input error and hard to get no overshoot. #3961

After taking the temperature up higher 1100˚c , all forms of usb power caused errors while AC was going through the SSR.

This really has me stumped, could it be the ssr?

mat

[atommat]

in reply to: Wierd Input error and hard to get no overshoot. #3960

More to report…

powering from a USB adapter or from my Macbook Pro seems to be fine and stable. I can boot both OSX and Windoze on my main computer and I get the same input errors with both operating systems. This leads me to doubt that the current supplied through the usb on my man computer is sufficient! I will try a powered usb hub tomorrow.

keep thinking

mat

[atommat]

in reply to: Wierd Input error and hard to get no overshoot. #3959

ok ive been trying to track this down some more. I have found that i can prevent the error by switching off the AC through the SSR or by disconnecting the ssr connection from the osPID altogether. if there is a grounding problem, then its something to do with ssr too. the erroring is not rhythmic either, it is very erratic.

obviously i need the thermocouple, the usb and the ssr!! even more confused now.

any thoughts?

mat

[atommat]

in reply to: Wierd Input error and hard to get no overshoot. #3958

I have also experienced faults identical to this. I have 3 thermocouples that all show the same symptoms, when they reach around 900 degrees, i get the “wall of red”. I dont get any errors at all with the USB removed, as soon as the usb lead goes in the input begins erroring on and off repeatedly. note: the error flashing occurs even without connecting with the ospidFE.

Im lost, ive checked all connections and tested all thermocouples with my handheld.

any thoughts or suggestions?

Mat

http://212.159.116.112/images/wall.png

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