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Hello everyone,
So I am finally getting around to building a heating blanket controller and realizing how little I know about electricity. I have searched the previous threads but most of the builds are across the big pond in GB and Scotland where I believe the voltage is different than the typical household voltage here in the US.
So I am checking out all these PID contollers on Amazon and this one appears to be what I would need https://www.amazon.com/dp/B0195V53X8?psc=1.
Can you guys give me your opinion? Im using two Protherm 6x34, 120 volt, 8.5 amp, 1020 watt blankets. Outlets are typical 110 grounded home wiring in the garage with 20 amp breaker.

Will the mentioned PID controller work for my purposes and what additional items would you suggest?

You guys always come through for me I hope you can help me out on this one. Thanks

Yes but it's only capable of controlling 3 amps. You need 15 to 16 amps. You'll need to add
an ssr, something like this one.
Ken

https://www.amazon.com/uxcell-SSR-25-3- ... PRJZS9BRH7

Thanks Ken. I was aware of needing this but did not know which to chose so thank you for this suggestion.

Does anyone have any experience with this product? https://www.amazon.com/dp/B01KMA6EAM?psc=1
Seems pretty slick.

Ah. if you look at the specs. seems to only read temp to 230 F. Other than that, looks good:)
Ken

I went with the PDI that LMII use in the controller they sell. It's available at http://www.auberins.com, model SYL-2362. They have excellent manuals for all their units online with sample application wiring diagrams. They sell another unit for slightly more that adds a timer function to shut things down after a set time. I also bought my box from them, as it was on sale and the K-type thermocouple panel connector. The 25A SSR, heat sink and 13A cables came from Amazon, and most other bits (switches, panel-mount 115v plug connectors, fuse folders) from Digi-key.






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This may not be useful if you are committed to using your existing blanket... but I bought a Keenovo heating blanket from a seller on the big river which has an integral controller. It works really well and is easy to drive. (I bent a side just today at 110 C using Maple and it went very well.
The price for this heater plus controller was not much more than what I paid for just the blanket in an earlier attempt.
I would expect this product to be available in the States ar 110 volts so worth a look.

Dave

Manual

http://blog.uvm.edu/cwcallah/files/2016 ... manual.pdf

Dave, the product sounds interesting. Do you have any contact info for the seller? I do have three heating blankets that are in near perfect condition that I am planning on using but I would still be interested in the product you are talking about. Meanwhile thanks everyone for their input and would appreciate anymore that anyone else has to give.

Tim , thanks for the info I am thinking of going with that exact product or the one with the timer for an additional $10. Do you mind me asking which Box you used?

I was wondering that, too. Did you buy the box with the cutout for the 16 din and just cut holes for the switches?

The box I used is still "on sale":
http://www.auberins.com/index.php?main_page=product_info&cPath=34&products_id=502
As you can see from my open box pic, the components are a tight fit. Measure twice, cut once. Yes, you have to do all of the cutting. The panels are 1.8mm aluminum, so pretty easy to drill and file holes to shape. The Digi-key listings for switches and panel connectors include spec drawings with exact cutout dims required.

I also have the wiring diagram I developed, if that's of interest. I actually thought of posting a tutorial on this, but it's not difficult if you're comfortable with wiring, soldering, etc.


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Anthony I can't lay my hands on a record of the purchase but I see that the brand is still around (in the UK) so I would expect you can find it where you are.

I spent a lot of effort with a home rigged control system - dimmer switch and thermocouple but it was very clumsy and detracted from the process of actually controlling the bend.

As I am starting a new build I again used it the other day and it performed really well.

Still doesn't mean that bends always work out right I have say though!

Dave

Thanks Dave and I know exactly what you mean. Sometimes the sides have different ideas then we do.

Tim,
thank you for the additional information and your wiring diagram would be super if you have it readily available. You're design is so clean and efficient. It looks tight but the fit and finish looks professional.
Anthony

I ended up building one after I saw the prices. I used an Arduino microcontroller ($30), temperature probe ($8), a LED temp readout ($10), and a relay ($20). It's simply controlling temperature by turning the power on/off. The temp is hard coded in the Arduino, but I built variables so I could change easily. (I don't usually change it) I also built a "drift" variable into the code so I could adjust how much the temperature can drift before it turns the power back on. (~5 degrees)

If you're a DIY'er, it's kinda fun. I can provide the code if interested. Looks like you have some good options based on your links though.

-Tim

You should find something suitable on here.
https://www.aliexpress.com/premium/sili ... t=0&tc=ppc
https://www.aliexpress.com/wholesale?ca ... controller

Yup, in the first link about 5 rows down is the Keenovo blanket, 1200 W (which is more than one needs but that's what it is) with the square box controller.

These all have got a lot cheaper since I first started looking.

Dave

Hmm, now that I offered a wiring diagram, I can't seem to find it -- thought I kept it with the PID manual.

The wiring diagram for the unit provided by Auber is a good start, using the hookup for a K-type thermocouple and connections to an SSR. The only change I made was to separate the controller and blanket circuits through 1A and 10A fuses, respectively, each with their own switch -- which I understand is how LMI designed theirs.

The controller circuit is wired using small gauge wire - 22AWG or even lighter. The blanket circuit uses heavier wire to handle the blanket load -- at least 16AWG. The C13 panel mounted connector on the back is fed by a 13A computer power cable. Output to the blanket is through a Nema 5-15P front panel mounted receptacle. Make sure you install a bolt in the bottom of the box as a common ground connection. I used insulated crimp connectors where possible, while fuse and power connectors were soldered.

If there's demand for a tutorial, I have several photos taken during assembly, and I suppose I could redraft the wiring diagram with little effort. Otherwise, happy to answer any questions on my unit.


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I would really appreciate a tutorial. I've seen dozens of pictures of the wiring, and somehow they are always blurry or key elements are hidden from view. I don't want to play around with that, and a nice tutorial would be excellent!

Responding to demand, I've cobbled together a tutorial, based on the construction of my own temperature controller. You'll find it in the Tutorials forum: http://www.luthiersforum.com/forum/viewtopic.php?f=10117&t=49239&p=649294#p649294
I've included a bunch of pictures, hopefully not too "blurry", and have given a parts list and wiring diagram. I hope some find it useful.

Tim thanks for all the information.. It is greatly appreciated.

Just to put a bug in your ear....

Have you tried side bending with no controller? Get your setup ready, plug the blanket in, and off you go....

Honestly - my side bending is going WAY better with no controller than it ever did with one. My controller fried halfway through bending sides and I just plugged the blanket straight in to Git Er Done.... It went so much better than it ever had previous that I never replaced the controller.

You just plug it straight in. Wait for the wood to start relaxing, and bend to the form. Done!

the issue with digital controllers is you know the heat at the point of the transducer. Heat blankets can have differing heat as the heat load is applied. I would not run one without a controller for safety reasons.
I don,t use the controller function until the wood has been bent then I use the controller for holding the lower temp ( under 250F ) to help dissipate the moisture from the bending side. Scorching happens through heat and duration. 375F is a safe temp as long as you don't exceed 6 min.
400F about 5 min
wood is stupid get it hot it will bend.

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