Hi Artem,

the detector has four cables connected: a telephone line, a serial
line, a printer-type line, and a USB-cable. I suspect it is easier to
use the simulator, which I ordered straight away ;-)

Best,
Tim

On Fri, 3 Feb 2023 10:22:39 -0500
Artem Evdokimov <artem.evdoki...@gmail.com> wrote:

> Hi Tim
> 
> One last option that's possibly even better, but requires rudimentary
> electronics: if you find the logic gate that flips from 0 to 1 (or
> backwards) upon thermocouple triggering below threshold temperature,
> you can simply supply +5V to the appropriate spot on the PCB, and
> Bob's your uncle.
> 
> To find the spot one has to trace the connection a bit, and have a
> handy voltmeter with a circuit probe, so when you put the TC into
> cold, it will register the signal. This assumes a fairly simple
> operation of the circuit - it may be that something much more
> sophisticated is taking place, like a signal on a CAN bus or god
> knows what else.
> 
> All the best,
> 
> Artem
> - Cosmic Cats approve of this message
> 
> 
> On Fri, Feb 3, 2023 at 2:16 AM Tim Gruene <tim.gru...@univie.ac.at>
> wrote:
> 
> > Hi Artem,
> >
> > the simulator is exactly what I was looking for - many thanks!
> > We did build a small circuit to generate the voltage (-0.586mV for
> > -15C), but this didn't work - probably, our circuit was too simple.
> > 12V input looks energetically better to me than using a peltier
> > chiller (I meant peliter, not piezo originally...)
> >
> > Second to that I like Mark's idea of a long cable for the couple and
> > stick it in the next -20C cooler.
> >
> > And yes - I already confirmed with cooling by liquid nitrogen, that
> > the concept works: when the thermocouple indicates cold enough, I
> > can operate the diffractometer, and hence install our new alien
> > detector. I was indeed looking for a long-term solution to make
> > overnight measurements.
> >
> > Thanks to everyone. I feel overwhelmed with the large number of
> > quick responses.
> >
> > Best,
> > Tim
> >
> > On Thu, 2 Feb 2023 20:19:32 -0500
> > Artem Evdokimov <artem.evdoki...@gmail.com> wrote:
> >  
> > > A basic Peltier element will likely work (may need a stack of two
> > > to reach -20) however the simpler option indeed would be to 'fake
> > > out' thermocouple input using a voltage, as described by Ivan.
> > >
> > > https://us.flukecal.com/Thermocouple-Temperature-Calculator
> > >
> > > And for $38 one can apparently purchase a thermocouple simulator
> > >
> > >  
> > https://www.brightwinelectronics.com/product/temperature-calibrator-k-n-thermocouple-generator-simulator
> >  
> > >
> > > Artem
> > >
> > > On Thu, Feb 2, 2023, 3:42 PM Rajkovic, Ivan <
> > > 000095c2dc0d4fa4-dmarc-requ...@jiscmail.ac.uk> wrote:
> > >  
> > > > Hi Tim,
> > > >
> > > > Not sure if this would work, but can you get a voltage supply
> > > > and connect it instead of the thermocouple? You would need
> > > > something to provide a few mV:
> > > > https://www.thermocoupleinfo.com/type-k-thermocouple.htm
> > > >
> > > >
> > > > Ivan
> > > >
> > > >  
> > > > > -----Original Message-----
> > > > > From: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> On Behalf
> > > > > Of Tim Gruene
> > > > > Sent: Thursday, February 02, 2023 11:57 AM
> > > > > To: CCP4BB@JISCMAIL.AC.UK
> > > > > Subject: [ccp4bb] small scale -15C chiller
> > > > >
> > > > > Good day,
> > > > >
> > > > > I would like to cool a K-type thermocouple down to -15C. The
> > > > > temperature  
> > > > does  
> > > > > not need to be very accurate, nor exactly -15C, just below
> > > > > that level.
> > > > >
> > > > > I was thinking of using a piezo-chiller, but they don't seem
> > > > > to be very  
> > > > energy  
> > > > > efficient.
> > > > >
> > > > > Could anyone make a recommendation for a simple device to cool
> > > > > the tiny thermocouple to -15C to -20C?
> > > > >
> > > > > For the details: we have an inhouse diffractometer with a dead
> > > > > detector.  
> > > > The  
> > > > > system is blocked, because the temperature of the detector
> > > > > needs to be  
> > > > below -  
> > > > > 15C. It is measured with a K-type thermocouple. I tested with
> > > > > liquid  
> > > > nitrogen.  
> > > > > The system show -64C (probably the limit of the thermocoupe)
> > > > > and I can  
> > > > operate  
> > > > > the system (and mount our new (brand-alien) detector).
> > > > >
> > > > > Thanks a lot!
> > > > >
> > > > > Best,
> > > > > Tim
> > > > >
> > > > > --
> > > > > --
> > > > > Tim Gruene
> > > > > Head of the Centre for X-ray Structure Analysis Faculty of
> > > > > Chemistry  
> > > > University  
> > > > > of Vienna
> > > > >
> > > > > Phone: +43-1-4277-70202
> > > > >
> > > > > GPG Key ID = A46BEE1A
> > > > >
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> >
> > --
> > --
> > Tim Gruene
> > Head of the Centre for X-ray Structure Analysis
> > Faculty of Chemistry
> > University of Vienna
> >
> > Phone: +43-1-4277-70202
> >
> > GPG Key ID = A46BEE1A
> >  



-- 
--
Tim Gruene
Head of the Centre for X-ray Structure Analysis
Faculty of Chemistry
University of Vienna

Phone: +43-1-4277-70202

GPG Key ID = A46BEE1A

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