Electronics guru needed...

[chris172]

Building myself a project box fridge controller with an STC1000 and had a bright idea to have all the wires detachable.

Been into Maplins today and bought a kettle plug socket for mains cable and a 2.5mm plug and socket for the temp probe.

Just had a thought ... would the plug and socket interfere with the signal from the probe?

TIA

Chris

[Pinto]

Wouldn't have thought so. You could always fit a small bit of earthed aluminium tubing over the STC cabling as a shield of you're worried.

[LeeH]

No it won't.

I would suggest calibrating it though as some of mine have been almost 1 degree out.

If you have a therma pen they come with a calibration sheet so I use that as my datum.

[AnthonyUK]

The NTC (Negative Temperature Coefficient) sensors are thermistors e.g. the electrical resistance changes with temperature.
As long as the connector doesn't affect the resistance which it shouldn't do, it will be fine. Shielding shouldn't be necessary with this type of sensor but won't hurt either.
Calibrate it once assembled as mentioned.

[Fastline]

Im thinking about making one of these, Does the ST1000s come with a suitable temp prob or is this bought separately

[LeeH]

Comes with one and is suitable to tape in the side so a FV. I wouldn't trust it in the wort.

You can but stainless probes from HBB.

[jimpy0]

Ay it comes with a probe [just built mine stc1000] just dont be looking for a +or- wire on it just bang it in and away you go.
i used the large project box from maplins and the display looks lost on the front, contemplating adding Led,s to show power on/heating/cooling but cant seem to find any blurb by someone thats already done it

[Fil]

to add indicator lights the easiest route is to use 240v ac neon indicator bulbs, and just wire them into the live feed switched by each relay..
http://www.ebay.co.uk/itm/12MM-PANEL-NE ... 4abc1ce367

edit simply wire up the lamps and add 1 wire to each of the relay terminals on the stc one lamp wired to the heating relay and the 2nd to the cooling..

to use low power led indicators it gets a bit more complex as each colour led needs a slightly different voltage so sledge hammer simple approach would be to use 2 x 12v dc power bricks
and the correct resistor for the colour of led switched by the power relay so again wired into the switched live feed for each relay.
as in here http://www.instructables.com/id/Choosin ... With-LEDs/

[alexlark]

i used the large project box from maplins and the display looks lost on the front

The STC's are quite small aint they! I was surprised when mine came back. I fitted it into the smallest box I could from TLC, it was snug but looks neat!

[themadhippy]

to use low power led indicators it gets a bit more complex as each colour led needs a slightly different voltage so sledge hammer simple approach would be to use 2 x 12v dc power bricks
and the correct resistor for the colour of led switched by the power relay so again wired into the switched live feed for each relay.

Or just use 240v AC leds,but 3 of them will set you back more than the tempreture controller.You could use a normal 10p led with a suitable dropping resistor,but its not something id recommend if you aint 100% in wot your doing

[jimpy0]

Cheers guys, once pointed in the right direction, google works wonders ---------------- no doubt with some extra effort i could have found cheaper
for those following suit you need to ask for the neons as not on display, but racked in the back.

http://www.maplin.co.uk/p/220-240vac-bl ... lamp-n92bn

1 red/heat
1 blue/cooling
1 green/power

[Fastline]

I've ordered the stc and a heater
I'm thinking if i get the other half a new fridge freezer she wouldn't say no to me having her old fridge, sounds like a cunning plan to me

[chris172]

thanks for the advice.

Was just worried the connector would have some sort of resistance factor which could affect the reading.

[jimpy0]

Just for tidiness keeping all my fridge questions in one pot so to speak ...................... Finally up and running pics later if wanted.

Are there any idiot settings for the stc 1000, even tho i class myself as a bit of a tech head, am struggling getting my head round adjusting settings [ i always struggled with digital watches back in the days kind of a blind spot].
do you set say F1 then power on each F setting to lock in, does F4 stay at 0
want
F1 - 20 degrees
F2 - 1 degree
F3 - 10 minutes
F4 - 0 ?

[Fil]

Set one parameter at a time with a power button press to save.

F4 is 0 until you change it, test the temp readings in a glass of water n ice avoiding touching ice with the probe tip for a 0C test point and the steam rising of a busy boil of water should register 100C , pages 16,17 in this pdf detail the tests file:///C:/Users/Me/Downloads/Thermapen-Guidebook-2.pdf

then adjust F4 if needed.

i would suggest 4-5 mins for the compressor delay F3 unless you notice it cycling and not hitting and remaining stable.. and then try upping the difference in temp it reacts to F2 allowing the temp to rise/drop by a larger value before either heat or chill is applied, especially if initially chilling a brew down when first sitting in..

for what its worth i need to refer to my stc1000 sheet everytime i have to change anything, and looked again today too