PID...? Help

[Victor N TN]

OK... I'm getting old, and I've been put to sleep in surgery a BUNCH of times. I've forgotten a LOT of stuff. But I'm having troubles understanding exactly what a PID controller is and how it works. Are they commercially available?

Can someone help me out with this?

Please and thank you for your trouble.
Victor


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[Beagle333]

It is a fancy thermostat that "learns" your pot (or heater or oven) and anticipates how much heat is needed to keep a preset temperature. It doesn't overshoot when it turns on and it kicks on in small pulses so you don't have dips in the temps either. It usually keeps things wihin 2° or less of the set temperature.

More explanation with the probability of repeating myself: If you are heating a cold oven or pot or lube heater from the start, it remembers from the previous session, about how much heat it took to get to that desired temp and slows down the heat as you get to the set value so you don't go way over and it also knows how much heat to keep adding along so that you stay at that temp.

It just removes one thing to think about when casting or lubing or baking (for heat treating or applying alternative coatings) and lets you concentrate on the task of making perfect boolits.

[Mike W1]

As above post says they'll keep your pot at a set temperature much closer than the factory thermostat does. And it repeatable too. Have included some links that have assembled units or kits. In reality there's not really much wiring to do to build one from scratch. I think $50 for parts wouldn't be too far off figure depending on what you want in it. Some judicious scrounging could even lower that figure. PM me if you'd like more info along those lines.


http://www.auberins.com/index.php?main_page=product_ info&cPath=8&products_id= 161

[Victor N TN]

Thanks for your help guys. I really appreciate it. I wasn't aware a controller built that economically could keep to a set temperature that closely. Can I use the same unit from the lead pot on the lube-sizer? Just adjust to a different temp? Or would I have to get a separate unit?

I think the next time I go to the blood doctor, I'm going to ask him if there is a blood test they can do for Alzheimer's Disease. My mother and her mother both had it in later years.

Thanks again.
Victor

[Beagle333]

Yes, they are commercially available. We even have at least one vendor here that makes and supports them. http://castboolits.gunloads.com/show...e-Controller-s
There might be others. I bought my first one and built two more.

You can use the same one for everything if you write down the settings after it "learns" that device (after just a few uses) and put those values in it whenever you change devices and it'll be instantly ready to go on the new one. I have three PIDs just so I don't have to change the values (I think there are only three to change, though..... but I'm lazy).

[Mike W1]

Yes you can use the same PID controller on different units but you'd want a little panel socket on the controller and a plug for the various thermocouples (TC's). Then it's just a matter of plugging in whichever unit's TC, and adjusting the temp. As above mentioned you'd be best off manually inputting the different values when you change units to control. It's actually much simpler than it sounds once you play with it a bit.