[OpenSPIM] Temperature control for the SPIM chamber

[edgar.escobar.nieto at ipt.fraunhofer.de]

 Dear Jan,

I already read the manual of the PID temperature controller and also has Solid State Relay output. When using the proportional
control mode, the output is a kind of a on-off switching, but controlling the percentage of time the output is on and off for every cicle.

"Proportional controls are designed to eliminate the cycling associated with on/off control. A proportional controller
decreases the average power being supplied to the heater as the temperature approaches setpoint.
This has the effect of slowing down the heater so that it will not overshoot the setpoint, but will approach the setpoint
and maintain a stable temperature. This proportioning action can be accomplished by turning the output on and off for 
short intervals. This “time proportioning” varies the ratio of “on” time to “off” time to control the temperature".

Since my aim is to integrate the temperature control in the easier way I will use this PID temperature controller and
the PT100 sensor. 

Thanks a lot for your feedback.

Kind regards,
Edgar
 _________________________________________________________________________

Fraunhofer-Institut für Produktionstechnologie IPT 
Edgar Escobar Nieto  
 

 
 
Steinbachstraße 17 
52074 Aachen 

edgar.escobar.nieto at ipt.fraunhofer.de 
http://www.ipt.fraunhofer.de
_________________________________________________________________________
 
 
 


-----"Krieger, Jan" <j.krieger at Dkfz-Heidelberg.de> schrieb: -----
An: "edgar.escobar.nieto at ipt.fraunhofer.de" <edgar.escobar.nieto at ipt.fraunhofer.de>
Von: "Krieger, Jan" <j.krieger at Dkfz-Heidelberg.de>
Datum: 21.09.2013 12:38
Betreff: AW: Temperature control for the SPIM chamber

Dear Edgar!

I would opt for the third one, as the first two will only do on-off regulation. The third one has a proper PID loop and the temperature will be more stable. Also it has an input for 3-wire PT100 (the others only NTCs), which is by far more exact and has wire-length correction, so you will have a very accurate temperature measurement. What I'm not so sure about (but also have no experience): It also seems to have a relais (i.e. on-off switching)  as output, not a linear output, so the regulator will heat in pulses, not continuously ... but maybe that won't harm, as you heat a lot of metal anyways, which will maybe damp away such pulses ;-)

I built my own controller ... but more out of interest, as the cost is more in the EUR100 range + work ;-)
It has a 4-wire PT100 input and a microcontroller + display + USB for control. The output is a MOSFET that can directly drive a resistor for heating with a PWM signal, so it can also provide a little heating power to keep a given temperature. The pro-side is that our SPIM-control software can control the device over USB and log the temperature during any measurement. The down side: the circuit is a little complicated and the PCBs carry a lot of standard SMD parts (which are not so easy to solder for non-experienced people).

cu
JAN


Dipl.-Phys. Jan Krieger
German Cancer Research Center (dkfz)
Department B040 - Biophysics of Macromolecules (Prof. J. Langowski)
Im Neuenheimer Feld 580
69120 Heidelberg

fon: +49 / 6221 / 42-3395
fax: +49 / 6221 / 42-3391
e-mail: j.krieger at dkfz.de
www: http://www.dkfz.de/Macromol/
________________________________________
Von: edgar.escobar.nieto at ipt.fraunhofer.de [edgar.escobar.nieto at ipt.fraunhofer.de]
Gesendet: Freitag, 20. September 2013 14:59
An: Krieger, Jan
Cc: openspim at openspim.org
Betreff: Re: Temperature control for the SPIM chamber

Dear Jan,

Thanks a lot for the information, it is very helpful.

I have seen that there are on internet some temperature controllers for ca. $25
http://www.ebay.de/itm/All-purpose-Temperature-Controller-STC-1000-Whit-sensor-/320628773067
http://www.autospeed.com/cms/A_112617/article.html

or this one that looks more complex
http://www.auberins.com/index.php?main_page=product_info&cPath=1&products_id=14

but I don't know if these kind of controllers are suitable for our application.

The advantage of this ones is that I wouldn't need to build the circuit for conditioning the
signal for the PT100 sensor and avoid writting a program for controlling the temperature.
So the temperature control would be independent.

What's your opinion?

Kind regards,
Edgar
_________________________________________________________________________

Fraunhofer-Institut für Produktionstechnologie IPT
Edgar Escobar Nieto




Steinbachstraße 17
52074 Aachen

edgar.escobar.nieto at ipt.fraunhofer.de
http://www.ipt.fraunhofer.de <http://www.ipt.fraunhofer.de/>
_________________________________________________________________________







-----Jan Krieger <j.krieger at dkfz-heidelberg.de> schrieb: -----
An: "edgar.escobar.nieto at ipt.fraunhofer.de" <edgar.escobar.nieto at ipt.fraunhofer.de>
Von: Jan Krieger <j.krieger at dkfz-heidelberg.de>
Datum: 19.09.2013 18:12
Betreff: Re: Temperature control for the SPIM chamber

Hi!

I'm attatching a picture of our chamber ... if that helps ;-) ... Have
you already decided on a temperature controller? As I mentioned before,
we have a homebuilt one and I'm using these PT100 to embed into the
sample chamber:
http://www.conrad.biz/ce/de/product/171961/Platin-Temperatursensor-in-Keramikhuelse-Heraeus-MR828-Heraeus-Nr-32-209-340-70-500-C-Keramikhuelse

For measurement in the chamber I found thin PT100 from stainless steel:
http://www.temperaturmesstechnik.de/fileadmin/user_upload/pdf/tmh-mantelwiderstandsthermometer-001.pdf
... but they are rather expensive (~55EUR+VAT)

About the foil: The ones I found a few years ago were all very large ...
if you find a small one, please let me know ;-)

Best,
JAN




Am 19.09.2013 13:49, schrieb edgar.escobar.nieto at ipt.fraunhofer.de:
> Dear Jan,
>
> Thanks for your feedback. So I will use the TO22 housing resistor
> and the PT100 temperature sensor. Or maybe instead of the
> TO22 housing resistor I will use a heating foil (also a resistor).
>
> Kind regards,
> Edgar
> _________________________________________________________________________
>
> Fraunhofer-Institut fr Produktionstechnologie IPT
> Edgar Escobar Nieto
>
>
>
>
> Steinbachstraáe 17
> 52074 Aachen
>
> edgar.escobar.nieto at ipt.fraunhofer.de _
> __http://www.ipt.fraunhofer.de_ < http://www.ipt.fraunhofer.de/>
> _________________________________________________________________________
>
>
>
>



[Anhang 'SPIM_manual_poster.pdf' entfernt von Edgar Escobar Nieto/Fraunhofer IPT]
[Anhang 'j_krieger.vcf' entfernt von Edgar Escobar Nieto/Fraunhofer IPT]
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