thermocouple and multi meter

That looks like the one that comes with a thermocouple module but I'm not 100% sure. If it is, you'll want to get some more wire because IIRC they were fairly short leads.
 
This thermocouple might be better suited as it has a higher working range up to 2300F which will easily be seen in most forge situations. You'll also want to look into a protective cover as fuel exposure can easily shorten the life of the probe. Here's the cover for the above TC.

This PID would work great for a simple pyrometer reading, and it also has the potential to be used as a solenoid controller in the future if you decide you want a temperature regulated forge.

Just some suggestions.

--nathan
 
cool i'll look into the pid and other thermocouple what do i need can you egulate the temp in an atmosphric forge ? thanks chris
 
I had an almost identical request from someone this morning. Here is what I told him:

What you need is a high temp type K thermocouple, a device to read it , and something to protect the thermocouple ( or it won't last long). Total cost should be about $100

http://auberins.com/index.php?main_...s_id=1&zenid=90b32ac5f8da355dc0ed454b403f29f8

http://auberins.com/index.php?main_page=product_info&cPath=3&products_id=39

http://www.auberins.com/index.php?m..._id=40&zenid=52501b8d6a7f7a3ad3287bd500a87dd8

A thermocouple plug/socket to allow for moving the PID to another unit when needed is a smart thing to put in when you first build it.
http://auberins.com/index.php?main_page=product_info&cPath=3&products_id=119

You could use almost any reading device, but a PID is cheap and whenever you are ready to make the forge/oven into a controlled unit , it will just need an output control (SSR) and a solenoid in the gas line.
The SSR is this one:
http://auberins.com/index.php?main_page=product_info&cPath=2&products_id=9

If you are just running a solenoid with it you won't need the heat sink, but if you ever use the PID to control an electric oven ( higher current) then you will want the heat sink,too.
http://auberins.com/index.php?main_page=product_info&cPath=2&products_id=45

I would suggest you get the SSR and heat sink now, and wire them into the unit when you build it. Then you can hook it up easily whenever you get a solenoid valve . It will make your life so much easier to have the forge controlled.A good tip is to put a 120V socket on the back of the box/cabinet you mount everything in. Hook the SSR 120V output to that. Then any device you are controlling will just need to be plugged in (Toaster oven, solenoid,small burnout oven, etc.) If you plan on controlling a high current device ( pretty much anything that draws more than three amps) you should put a small cooling fan (computer type) in the cabinet to pull air through the heat sink fins.

That is pretty much it.
Stacy
 
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Stacy, that is a great idea to build the universal control unit and use it for different applications. Do you need to reprogram the PID when you switch between an electric kiln and solenoid controlled gas forge?
 
No need to re-program the PID unless the desired parameters change for a different device. To move from forge control to toaster oven control is merely the change of the power plug to the new device, and plugging in the new devices TC plug.
If you are running a HT oven, remember that a kiln will have a different plug than a toaster oven. You would have a standard socket and a socket for your kiln, side by side.
The direction I am trying to go in designing things is a modular system, instead of hardwired. Each thermocouple has a TC plug and TC wire . Each fan,oven, solenoid,etc. had a power plug. The control unit will have all the control systems desired and you just plug in the necessary peripheries. This allows the control to be used for several devices, and allows things like changing thermocouples,fans, or upgrading to a better tempering oven to be simply done without having to tear the unit down. It also allows the control to be quickly removed when the work is done, and stored in a proper environment for electronics. I have added quick connect fittings for the gas lines as well, so the tank has a delivery hose that snap to the input , and the forges have a supply hose that snaps into the output. If running a forge without the controller, the two hoses can be connected to each other.

The way to plan the build for such a system is make a list of all the devices you could conceivably control, and have the proper sockets and connections built in. Use proper gauge wire connectors and spade lugs ( HF wire connector kit?) to connect the components to each other. This allows changes and additions while designing the unit to be an easy thing. The additional cost is small, but the versatility and convenience is huge. Make the unit as a breadboard project to start with ( no cabinet). Ideas will pop into your mind and many changes will come to pass. Don't build it into a cabinet until you are fully pleased with the design and capabilities. At that point reconsider all the hookup and disconnect necessities, and provide an enclosure that is suitable for the final project. Allow extra room for future additions ( I bet there will be some). In a dedicated shop, with stationary equipment, the unit may be a panel mount ( salvaged circuit box works great), for a shop where things are moved around and in and out of the shop, a portable unit ( large tool box works great) is desired.

I am still working on the final build of "The Ultimate Controller". As soon as all the changes are worked through, it will be posted with complete build instructions, schematic and flow diagrams, and a parts list ( with suppliers).

Stacy
 
thnaks stacy i have a couple of new questions for you how much more expensive would it be to just make it temp controled now and what kind of solenoid do i need
and how do i set it all up i think it goes like this
themocouple in forge
pid atached to thermocouple and solenoid valve
solenoid valve in propane line (after the regulator?)
then i just set the temp i want o the pid and the valve adjust the flow of propane acordingly ? hopfully im a t least a little close thanks agian chris
 
That is the basic principal. There is a little more to setting it up and running it. PID control works best on a blown forge. The two-stage controller I developed has a high and a low setting. The flame cycles between high and low, instead of on and off. Much better regulation and no scarry ignitions when the PID cycles on.

It will cost very little more to set it up initially. Maybe an extra $50-100, depending on how fancy you do it. The quality of the forge atmosphere, control, and savings on fuel will make that a good investment.
The solenoid valve can be found on ebay for $20-50. It is a 120VAC, 1/4", NC, fuel gas solenoid valve. You will need two fan controls ( instead of one)- about $5 each on ebay, and two needle valves (instead of one) - $7 ea. from Darren Ellis, and a few pieces of 1/4" pipe fittings. All the other things are the same as for a regular PID and thermocouple setup.

I am at work. I'll post some details and diagrams tonight.

Stacy
 
sound like i might want to wait until i get a forge with a blower for the solenoid vlave but i do think that ill set everything else up as you suggested thaks agian chris :)
 
Stacy, is an "SSR" the PID I need for my forced air forge to regulate the temp so that it's not an "on/off" type set up? Is this the thing I need that just reduces the amount of propane into the forge in order to regulate the temp?
Thanks,
Mitch
 
I believe an ssr is a relay. It's used with the pid so the full current of the device isn't going through the pid itself. I would like to setup a 40" tempering oven, can one pid controll/read multiple ssr's/thermocouples?
 
john0270 said:
I believe an ssr is a relay. It's used with the pid so the full current of the device isn't going through the pid itself. I would like to setup a 40" tempering oven, can one pid controll/read multiple ssr's/thermocouples?
Click to expand...

Thanks, John. I'm waiting for Stacy to post all the detailed specs.:thumbup:
- Mitch
 
silver_pilate said:
This thermocouple might be better suited as it has a higher working range up to 2300F which will easily be seen in most forge situations. You'll also want to look into a protective cover as fuel exposure can easily shorten the life of the probe. Here's the cover for the above TC.

This PID would work great for a simple pyrometer reading, and it also has the potential to be used as a solenoid controller in the future if you decide you want a temperature regulated forge.

Just some suggestions.

--nathan
Click to expand...

Nathan, Can I plug this PID thing into a 120v outlet?:confused:
Thanks again,
Mitch
 
Nathan,
Another question on this if you please.
How complex is calibration on a simple PID and thermocouple installation?
Thanks,
Patrick
 
I'll try to give a more detailed answer tonight.

The SSR is a Solid State Relay , it switches the power on and off to the load device when activated by a low voltage/low current signal from the PID.

It only requires one PID to controll a forge. Multiple burners still have only one solenoid.

PID calibration for just reading temperature is very simple.

The savings in propane is from running a blown forge and having the burner set to produce only the required amount of heat. Instead of an off/on, the setup I have designed goes from high to low. The flame never goes out, and thus the temperature control is much tighter and more even. The forge atmosphere is much better,too.

Stacy
 
Mitch, if the PID is rated for 120V opperation (they do make 220V units), you should be able to wire it up to a pigtail inside a project box and be good to go.

As for set up, it's not that bad. The PID's typically have a fuzzy logic learning feature that allows them to correct overshoots, undershoots, etc. over time if the parameters remain consistent. However, my oven overshoots, so I set temp about 50F below target, and then sneak up to the target temp slowly so I don't overshoot too much.

If you're just using it as a pyrometer (thermocouple hooked to PID just to read temp), as soon as you have the TC hooked up and the power running, you will have a temp reading.

--nathan
 
silver_pilate said:
Mitch, if the PID is rated for 120V opperation (they do make 220V units), you should be able to wire it up to a pigtail inside a project box and be good to go.

As for set up, it's not that bad. The PID's typically have a fuzzy logic learning feature that allows them to correct overshoots, undershoots, etc. over time if the parameters remain consistent. However, my oven overshoots, so I set temp about 50F below target, and then sneak up to the target temp slowly so I don't overshoot too much.

If you're just using it as a pyrometer (thermocouple hooked to PID just to read temp), as soon as you have the TC hooked up and the power running, you will have a temp reading.

--nathan
Click to expand...

Thanks, Nathan. I'm starting to get the idea. (Now I just need Stacy to spoon-feed me the parts list and wiring set up.:) )
 
I used a simple project box from Radio Shack, a pigtail with the appropriate plug, with fuses and a switch wired in before the PID. Pretty simple once you examine the wiring diagram.

--nathan
 
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