Digital Thermostats

[michael_aussie]

FWIW, these are still going cheap. I bought a couple. They are indeed the STC1000's. I have to get another for Hatchy! Good little unit

omg $16.28 including postage.

That is soooo cheap!!!!

and I thought I was kissed on the arse buying them about 6 months ago at $33 each??

 

[Wolfy]

and I thought I was kissed on the arse buying them about 6 months ago at $33 each??

That was what I just paid


... for two of them.

 

[Deebo]

As promised, this is the list of part numbers from Jaycar I used to wire up my stc-1000:

1 x HB6012 Black Enclosure (197x113x63mm), $6.95 Ea
2 x PS4094 SKT PNL Mains Aus White, $7.95 Ea
1 x HM3204 Terminal block, $4.95 Ea
1 x PP4009 Plg Pnl IEC320 Snap In, $4.95

Note that the terminal block I brought is a 12way 60A, so you could go smaller if they have stock (which they didn't at my local) and I already had the wire and power cord to hook it all up.

Thanks for this list, just ordered the temp controller and the bits from jaycar online.

 

[bigfridge]

The reason I am wanting to use a different probe is that the one with the unit is a plastic/rubber tip type thing and I am dubious about dangling it in the pot. Also, I could drill a hole in the pot for a thermowell, but I am a tight ******* and want to do this as cheaply as possible. I paid something like $5 for the new K type sensor and it can be mounted in the wall of the pot weldlessly, so I was hoping it would work. If not, I can always drill the hole out to take a proper thermowell and just use the original sensor.

Lucky for me I like mucking about with this sort of thing, so it could provide a few hours of entertainment

I beleive that you are out of luck.

Controllers for ambient temperatures (ie 0-100 Deg C) use NTC Thermisters as they provide a good accuracy (less than 0.5 deg) and are very cheap (only a few cents each).

The Type K termocouples are used for temperatures up in the hundreds or thousands of degree where being a few degrees out is not significant.

NTC Thermisters are resisters whose resiistance value changes with temperature - NTC stands for Negative Temperature Coefficient so their resistance decreases as the temperature increases. This means that the controller needs to measure the temperature probes resistance and any use a polynomial equation to calculate the temperature.

Thermocouples use 2 different metals to give a voltage that is proportional to the temperature so the controller just has to convert the voltage to temperature.

They are different things used for different purposes by measuring different physical characteristics with different accuracy.

HTH,
Dave

 

[Deebo]

As promised, this is the list of part numbers from Jaycar I used to wire up my stc-1000:
1 x PP4009 Plg Pnl IEC320 Snap In, $4.95

What is the correct way to connect wire to the above part? (On the wiring side it has the 3 pins with holes through them) but no screw type connection etc.

 

[stux]

What is the correct way to connect wire to the above part? (On the wiring side it has the 3 pins with holes through them) but no screw type connection etc.

I used http://www.jaycar.com.au/productView.asp?I...SUBCATID=1001#3 in my build

I just soldered the connections and used heat shrink insulation

 

[Wolfy]

What is the correct way to connect wire to the above part? (On the wiring side it has the 3 pins with holes through them) but no screw type connection etc.

On my 12V work (so much less critical than working with 240V) I strip the wires, push the wire through the hole and then twist it back over itself, add a good dob of solder so that it seals the hole and the wire and then use shrink-wrap to cover, protect and insulate it.

Something that I've noticed (with various appliances like washing machines) is that they solder the wire onto a small (plastic covered) plug (which I'm sure you can buy at JayCar, they are small/cheap/nasty) and use that to slide onto the pins.

 

[dcvin]

Sorry to bring an old thread back to life but was wondering if a bar freezer would be able to turn that into a incubator using the STC-1000?

Or would i be better off buying a fridge?

 

[claypot]

Sorry to bring an old thread back to life but was wondering if a bar freezer would be able to turn that into a incubator using the STC-1000?

Or would i be better off buying a fridge?

Hey mate,
No problem with freezer. Would actually be better than a fridge as will most likely have better insulation, thus less run time and cycling.
I am looking to swap my beer serving fridge to a freezer for this reason, as my fridge is in the shed and struggles to keep temp during hot Adelaide heat waves.
The above temp controllers are good to keep temp with in 1 deg dependinging on set up. If you need a finer control a PID temp controller with a PT100 probe would be good to with in.2 degree depending on set up.
Cheers, Clayton.

 

[hirns]

Well, I've just wired up two of these ready to go. I've found heaps of threads on temp probe placement in relation to fermentaion, but nothing in relation to simple temp control for a serving fridge. My genuine kegorator has it behind the grill just off the bottom, whilst my bar fridge has the probe about half way up. I understand that cold air sinks, but that does not address the question of best position for overall controll. I'm guessing middle to even out the temp difference beteen top and bottom. Suggestions or am I splitting hairs???

 

[pk.sax]

Mine's in a bottle of water that sits on the hump.

 

[hirns]

Thanks PracticalFool,

I had read that, just needed reminding.

 

[Wolfy]

Suggestions or am I splitting hairs???

You're probably splitting hairs.
There is not any fermentation to increase the internal temp of the serving-fridge, so the only time it's going to change is when you open the door or due to cold-loss through the insulation, so the inside temperature should equalize quite quickly no matter where you measure it.
I have my fridge probe wedged between two kegs and insulated with a bit of foam, so in theory it's measuring the exact temperature of the beer.