Inexpensive Temperature Controller

[another_jim]

I posted this to a lever thread, but thought I should give a heads up here.

Dwyer Instruments (Love division) is manufacturing and selling a thermocouple temperature switch (similar to the Brewtus stock controller) for $50. This is a simple on/off control with programmable hysteresis (e.g. turn boiler on at 122C, off at 124C). The really nice feature is that it includes a 16 amp rated contact, enough to drive most home espresso machine heaters comfortably, therefore does not require a separate SSR.

Info: http://www.dwyer-inst.com/htdocs/PDFFILES/iom/temperature/TCS_iom.pdf

To buy: http://www.dwyer-inst.com/htdocs/temperature/SeriesTCSPrice.cfm

For many applications, one wants easily settable reasonably tight temperature control, but the final shot temperature has so many other factors that PID is overkill. Steam boilers on dual boiler, lever or HX machines, as well as the boilers on smaller machines like the Silvia, come to mind. This unit could cut the cost to 1/4 of a PID, and simplify installation.

I've bought one to use with my Peppina. I will also assess whether it's useful for the Tea's steam boiler and for an ultra secret temperature control scheme I'm contemplating.

OK, you've twisted my arm. See my post in Knockbox.

[lennoncs]

They also make a dual PID in 1/32 DIN format.
Nice company to deal with, they return calls and will actually give you an opinion.

Sean

[barry]

fwiw, i've been evaluating these as low-cost displays for real-time brew temperature readouts. they're pretty nice, but are not a standard DIN size (no big deal), and are only 3 digit so you can only deal in whole degrees. i've got one hooked to my home marzocco right now. btw, i'm also going to get a couple for roaster control/display.

[another_jim]

They also make a dual PID in 1/32 DIN format.
Nice company to deal with, they return calls and will actually give you an opinion.

Sean

Cool? How much? I'm looking for a dual loop cascade controller for my roaster.

[snoboy]

Sounds like a good item for preheaters and the like. I've been thinking about adding a thermoblock to Silvia, but wondering what to use for the temperature control.

[cannonfodder]

I have ordered one unit to use as a temp controller on my lever machine, but I got to thinking (be afraid, be very afraid) would the thermocouple unit make an acceptable replacement for the good old pressurestat?

I looked at the specs, but not being an EE, I was unsure of some of the specifics. It looks like you have a ± of 1 degree on the accuracy, I can live with that. But my question, what is the dead band on the unit? It looks like you can set the time between heating sequences as well as the threshold. So if I were to order another unit, mount it in the front of my Isomac (like the brut) could I gain a tighter temperature control on the boiler? I would be mounting the type K TC in the boiler via an omega lock fitting.

[another_jim]

I have ordered one unit to use as a temp controller on my lever machine, but I got to thinking (be afraid, be very afraid) would the thermocouple unit make an acceptable replacement for the good old pressurestat?

I looked at the specs, but not being an EE, I was unsure of some of the specifics. It looks like you have a ± of 1 degree on the accuracy, I can live with that. But my question, what is the dead band on the unit? It looks like you can set the time between heating sequences as well as the threshold. So if I were to order another unit, mount it in the front of my Isomac (like the brut) could I gain a tighter temperature control on the boiler? I would be mounting the type K TC in the boiler via an omega lock fitting.

Way I read the PDF, one can set the deadband by 1C or 1F steps. Commercial pressurestats translate to about a 2C to 3C deadband; there's a new Mater or Ceme tight deadband model that is down to 0.1 bar, or just under 1C. In an HX machine, with all the intermediate buffering, the major advantage of a pressure switch is that you can set it easily and repeatedly. However, the benefit of such quick changes is unclear to me, since the final brew temp has so many intervening variables. I'm more inclined to use one as a grouphead temperature controller.

[cannonfodder]

I know my pstat has a dead band adjustment, I just have not played with it. Right now it is running about .2 bar, on at 1.1 off at 1.3. With a HX machine, I do not think I would really be gaining much other than the gee whiz looks cool factor. I could make quick boiler adjustments, but with an E61 group that is almost counter productive unless you used it on the thermosyphen loop to regulate GH temp, as you suggested. If I entertained it may be helpful, I could run the temp up for steaming a lot of milk, but it is just me.

Maybe if my pressurestat goes bad one day, or I just get real bored, I might give it a try. I have the stock Ceme in it (I believe that is the one I have) but I do not know if it is the tight band unit. The machine is about 8 months old. I am going to play with it more this week during the holiday. I want to change my boiler and HX preheat loop insulation.

[skyryders90]

there's a new Mater or Ceme tight deadband model that is down to 0.1 bar, or just under 1C.

Where might one acquire one of these?

[malachi]

Espresso Parts NW I believe has them.

[another_jim]

A note on these units' availability: They do not ship immediately; mine's scheduled for 12/28.

[skyryders90]

A note on these units' availability: They do not ship immediately; mine's scheduled for 12/28.

Do you have the specific part number? It's not at all clear to me which ones on there are "low deadband" - I was told yesterday that the CEME with the adjustable deadband was, in fact, the "low deadband" model simply because you could crank the deadband down.

[cannonfodder]

A note on these units' availability: They do not ship immediately; mine's scheduled for 12/28.

Odd, I ordered mid day the 21st, it shipped that evening and arrived today.

If I understand this correctly, I have the two type K TC inputs (+ and -), two power supply inputs and a NC (normally closed) COM (common) and NO (normally open).

The + and - probe inputs are straight forward. I purchased the 115Vac unit so I can power this right off the 110 line on my power switch. I am not sure about what I should hook up to the NC, COM, and NO line.

Any help would be greatly appreciated, photos are even better. I don't want to release the 'blue smoke of mystery' from the box or my machine.

I have the next few days off work so I can pick up a TC line tomorrow, drill and tap my boiler, mount the omegalock fitting and probe with ease. But I could use a hand to make sure I get my lines correct. I will take photos of the process, test and post the results if you can give me a hand on the wiring.

[another_jim]

I am not sure about what I should hook up to the NC, COM, and NO line.

This set is the output -- a switch. COM is attached to the power. NO (normally open) is the side of the switch that is open when the relay is denergized and closed when it's energized. The NC contact is the other side of the switch and is closed when the relay coil is denergized. I read the documentation: "the output is on" to mean the coil is energized, and that you connect to the NO side if you follow the heating and cooling declarations in the setup parameters as outlined. However, I personally would take an ohmmeter to the contacts, and just run it on the bench at room temperature to make sure.

Why is it everytime I bang the drum for a product, I'm always the last to get it? Maybe I should just shut up.

[cannonfodder]

Thanks Jim, makes sense now. I don't know why I got this one before you. Did you order the same model TCS-5010?

I have to run back to work to get my lever machine and I will get it put together tomorrow. I will post the results on my PID lever machine thread.

[another_jim]

I got the 5011, I'll put up with farenheit if it gets me the thing a month earlier! Come to think of it, it makes for a tighter deadband too.

I'll be interested to read your result.

[cannonfodder]

I was wondering if you went with Celsius. Their web still showed it as not a normal stock item, guess I just got lucky.

[barry]

jim,

don't fret the ship date. when i ordered mine a few months ago the indicated ship date was a couple of weeks out but the controllers showed up in a couple of days. iirc, they ship out of chicago, so you should have it pronto.

[another_jim]

jim,

don't fret the ship date. when i ordered mine a few months ago the indicated ship date was a couple of weeks out but the controllers showed up in a couple of days. iirc, they ship out of chicago, so you should have it pronto.

Thanks for the tip. I emailed them to check; so I'll know what's happening soon. In the mean time, I'm practicing my 5/9ths multiplication table.

[lennoncs]

Cool? How much? I'm looking for a dual loop cascade controller for my roaster.

Hi Jim,
I missed this post somehow

here is a link to their page for the dual loop control http://www.love-controls.com/controls/32dz/32dz_frame.html

I will get a price today.

Sean