PIDs?

[jonewer]

What is a PID? Is there a numpties guide somewhere for what they do and how they do it?

I'm keen to get some kind of auto recric going but dont know anything about temperature control.

Thanks.

 

[Vossy1]

A PID is an electronic controller which allows you to control circuits for heating and cooling, depending on device bought.

You set the PID/device to a set temp, say 20 deg c for fermentation

You set how far either side of 20 deg c you want it to work at before triggering heating or cooling circuits, ie, 1 deg c either way.

When the set temp is exceeded the cooling circuit will be triggered. This will open a circuit which powers a cooler of some sort, which will cool your beer in some way.

Example, a beer cooler used in conjuction with a product coil, the beer cooler pump is turned on, and cold water flows through the product coil which is immersed in your beer thus cooling it.

The temp in the beer falls below your set temp on device which will trigger the heating side of the circuit.

Example 1, you have an aquarium heater in your beer, it will turn on and raise the temp of your beer
Example 2, you have a light bulb in the cupboard where your fermentor is kept, it will turn on and raise the temp of your beer by raising the ambient temp and thus the fv

Examples of PID/devices, ATC 800, ATC 800+, Tc 10, all available from Fortrex on E-bay, and various PIDS via Virtual Village, again E-bay and there's a link in our links section which will entitle you to a discount on their products.

Fortrex
Auberins are also a very good supplier and their service is very prompt, and their prices hard to beat :thumb:

Well worth checking the forum for the PIDS/devices used rather than ordering a lemon

 

[jonewer]

Thanks Vossy,

So to make a recirc system, I need to connect a PID to a kettle or something to maintain my mash temp?

 

[prolix]

As vossy said they control temp, atc 800 and tc 10 are simpler than pids though, they work on oh it's that temp off or on and have hysterysis overshoot, good pids will hit the temp and stay there as the first time you use it for a system it learns the system and nows when to turn off in order to arrive at a temp with out over shoot and when to turn back on to avoid to much cool down etc.

I use the auberins ones and they are great (vossy you missed the www bit on the link ) these ones

they are great, though really scary before you have used them and I don't like cables all over the place so slashed out on these
and you need some of these to switch the heater on and off as the pids do not do large loads.


I had to but a 1/4 npt thread cutter from the bay to make fittings for them but have loved ever minute of it.

You can get them much cheaper from virtual village on the bay but I wanted the quick release plugs.

 

[jonewer]

Seems to be seeeriously beyond my DIY skill level!

 

[prolix]

Like AG it seems a lot harder looking in than it is when doing it.

 

[ano]

Vossy, is the main difference between a tc-10 and say an xmt-7100 that the tc-10 doesn't have a feedback loop?

The way you explain PIDs it seems like you're referring to little more than digital thermostats?

 

[Vossy1]

Vossy, is the main difference between a tc-10 and say an xmt-7100 that the tc-10 doesn't have a feedback loop?
The way you explain PIDs it seems like you're referring to little more than digital thermostats?

Prolix has that one covered

atc 800 and tc 10 are simpler than pids though, they work on oh it's that temp off or on and have hysterysis overshoot, good pids will hit the temp and stay there as the first time you use it for a system it learns the system and nows when to turn off in order to arrive at a temp with out over shoot and when to turn back on to avoid to much cool down etc.

I use the auberins ones and they are great (vossy you missed the www bit on the link )

:thumb:

 

[jonewer]

Cant you just fit some kind of thermostat to a kettle and pump the wort through that?

 

[onelegout]

A thermostat wouldn't be able to hold the temperature stable, as they're not designed for that level of precision.

 

[caerleon]

I could tell you all about how PID's work, but it would bore you! :ugeek: Afraid it was part of my Engineering Degree :ugeek: :ugeek: :ugeek:

If you need some bedtime reading then this link should help!

http://www.engin.umich.edu/group/ctm/PID/PID.html