Oh..nevermind. There are dozens of these on ebay in various makes and models. They look very nice; the trick will be getting a good one cheap.
Originally Posted by Wayne
Those might work but would require a separate temperature control which I am incapable of MacGyvering without specific (and very simple) instructions.
Don't let my tampering with the ViaAqua lead you to believe I have even a smidgeon of electrical knowledge. I know not to bring a toaster into the bathtub, and that's about it.
Originally Posted by chuck94022
Wayne, the PID controller is actually very simple to work with. If you buy one with an integrated solid state relay, and you buy a PT100 temperature probe, and you buy one of those immersion heaters that I mentioned, here is what you have to do:
Originally Posted by Wayne
1. Clip the plug off the power cord of the immersion heater. That will expose two wires. Strip the insulation off those wires, and connect them (probably a screw type connection on the PID) to the relay outputs.
2. Connect the three wires that come off the temperature probe (two will be one color, the other will be a different color. Mine is black-black-red) to the PID to the probe inputs.
3. If the PID doesn't come with a power cord, buy one from your local store, or (better!) scavenge one from some discarded electronic junk in your attic, and connect the wires to the PID power input terminals (also probably a screw-type connection).
That's it for the electrical connections, it is dirt simple.
Of course, I didn't mention that you probably want to get some sort of plastic box and mount the PID controller inside it, so that the bare wires coming off the back aren't exposed. But that's extra credit for you to figure out...
Here is a typical PID controller, very similar (maybe identical) to the one I have: http://www.auberins.com/index.php?ma...roducts_id=237
You can probably find one similar, but cheaper, on *bay or Amazon. You might even find one already in a box, or with the PT100 probe included. PT100 probes are also easy to find on *bay or Amazon.
Here is the connector diagram for the controller linked above:
As you can see, for this controller, in my instruction 1 above, you'd connect the heater wires to pins 6 and 7 (in no particular order).
For instruction 2 above, you'd connect the two same-color wires to pins 3 and 4, and the different color wire to pin 5. For instruction 3 above, you'd connect your power cord to pins 9 and 10 (again in no particular order). The "pins" are probably little screws that you unscrew, put the wire under, and screw down tight.
Easy! The only caution I would give. Don't plug in the power until everything is fully connected and you have assured that no stray copper strands from any of the cords cross over and touch any other pin. And once plugged in, don't touch any of the pins or bare wires! Ouch!
Edit: If you can't be bothered with a separate box, here's the MacGyver solution: wrap the entire PID controller from front to back (keeping the display visible) with electrical tape, making sure the back of the controller is covered with a layer or two of tape, and continue wrapping for a few inches down the length of wires. It will be a little messy from tape glue if you ever have to unwrap it, but you won't.
Tools needed for all the above: a screwdriver, wire cutter, and wire stripper. The latter two can be done with a sharp knife, but you can get a cutter/stripper from Radio Shack for not much cash and it will make things cleaner.
Edit 2: One more thing (ok, is this McGyver or Columbo?) : The PID controller's LEDs emit light and will affect your film if you are doing a lights-out process like dip and dunk. I simply cover the face of the PID with aluminum foil when doing that sort of process. The foil is light tight and simple to remove.
Last edited by chuck94022; 11-21-2013 at 03:09 PM. Click to view previous post history.
On that previous post: I just used that particular PID device as an example of using a PID. Note however, that particular PID specifies that it can only handle 300 watts of output. This limits the wattage of the heater you use. When you select a PID, either find one with a built in SSR that handles the amount of heater wattage you'll use, or get a smaller heater, or use a PID with a separate relay that can handle more power (the PID output, instead of connecting to the heater, will connect to the relay. The relay will connect to the power cable and to the heater. It will also have easy to connect screw-type connectors, so no soldering will be necessary, and the connections would be as simple as the instructions I gave above.
Thanks for the instructions. I'm a bit too wary of my electrical skills to attempt that right now, but maybe in the future.
I discovered that with pliers I could turn my aquarium heater control post past the stop. Problem solved! Or so I thought. It actually didn't make a bit of difference. I was left with only two choices-try to force the trim screw past its stop, or put it back together before I ruined a perfectly good heater that serves me very well for B&W. I chose the latter.
I think my next step will be to try a Wallly Mart heater which we already know can be MacGyvered up over 100. If that doesn't work I'll revisit the home-brew idea.
But what I would like is a simple control with a probe, that I can plug my existing metal heater into without having to hard wire it. Then I could just leave the heater's probe out of the water and let the controller's probe turn it on and off. I'd gladly pay a few extra bucks not to have to wire one myself. But I don't want to pay 75 or 100.
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Well I got one (a small water bath) pretty cheap; now I just have to wait for it to arrive and find out if its a any good. I see more of these in my future.
Originally Posted by Wayne
I'm intentionally bumping this old thread since I've got a couple of build notes and also would appreciate help with a problem I'm running into.
I purchased a PID, SSR, and thermocouple combo set from Amazon for ~ $30. Quick caveat: Even though the set came with a thermocouple, it did not come with the probe that hooks into the thermocouple. That was another $6 or so. I've wired everything up with a $6 immersion heater from Amazon.
I drilled holes in a medium-sized storage container (1/4" hole for the temperature probe, and 7/8" hole for the immersion heater), installed the hardware, and waterproofed everything with clear silicone. Wiring everything up was straightforward, and drilling holes in the storage container was relatively pain-free. The storage container cracked a small amount when I drilled the 7/8" hole for the heater, but the silicone has adequately sealed that crack.
Circulation inside the container is provided by the cheapest aquarium powerhead I could find on Amazon, set to low. It was ~$7, and works very nicely.
The PID is correctly turning the immersion heater on when the temperature probe tells it the water temperature is below my set value. The PID correctly realizes when the water temperature exceeds the set value, and does not send power to the immersion heater.
Here's the problem I'm having: I can't get the system to raise the water temperature past 20.0C. It holds nicely at this value, but it's keeping the immersion heater on almost nonstop to hold the temperature there (at least that's how it was working this cold morning). I feel like the SSR and/or the PID isn't sending the immersion heater enough juice to allow it to heat the system up past 20.0C.
(Ironically, I'm shooting for a 21.1C process temperature ... if I can't get the system hotter, I'll just change my process to 20.0C.)
Overview of system. I'm going to put the guts in an enclosure when I have the device working well.
Detail of the PID, SSR, and immersion heater covered in silicone.
SSR with electrical numbers that don't mean much to me, and that I suspect may be the problem.
Overhead shot of the layout of the aquarium powerhead, immersion heater, and temperature probe.
Detail of calibrated thermometer holding steady at 20.0C.
PID display showing measured value in red and set value in green. Output light on showing power to the immersion heater.
You got all that hooked up to a GFCI?
MacGyvering a tempering bath for color development
Yup. $12 GFCI from Home Depot. I'd like to find a way to correctly ground the thing. An electrician I ain't, but I know enough to have used a GFCI.
Don't you just ground it via the uninsulated lead?