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Hi all,

I had this thing lying aground hidden in the shop for a couple of years or so. I bought it 2nd hand. So far I only used my bending iron , mostly because that's how i've learnt to do this.
I have never touched electrical stuff beside changing the ocasional light bulbs and consider myself pretty illiterate.

I searched a bit and folks talk sbout relays and thermocouples, which I know nothing about and don't seem to have.
So, do you think this will work? Any tips? Or do you think I'll just get myself shocked and burnt?

Sorry if this is all to shaky and vague... Been a long day and I'm sleepy...

Thanks in advance,
Miguel.

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member of the guild of professional dilettantes

Hmmm. Looks familiar
http://www.luthiersforum.com/forum/viewtopic.php?f=10117&t=47715
Should be a label on the side showing model.
Not got the 40A solid state relay and heat sink? - Ebay is your friend, search "40A SSR relay heat sink"
Inexpensive from far east, stuff from Hong Kong seem to arrive a bit quicker than from China IME.
I'm using a thermocouple similar to this https://www.amazon.co.uk/Nylon-Braided-Thermocouple-Temperature-Sensor/dp/B00C97FIFE/ref=sr_1_17?ie=UTF8&qid=1476468740&sr=8-17&keywords=thermocouple K type is important.
(Modified as per post)

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Thanks Colin! aparently I have the relay - even if I didn't knew it. So, I'm just missing the thermocouple. I'll look into it. Frankly, I don't even know what the thermocouple is for, I wonder if this will work without it.

Anyway thanks for the info !

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member of the guild of professional dilettantes

You need the thermocouple. It's placed in the "sandwich" and tells the PID what temperature the heating blanket is at, that way the PID can do it's job, cycling the power on and off to hold the temperature and to start the count down timer.

Here's one I did last year. viewtopic.php?f=10117&t=45009

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What Rod said.
Except I use a kitchen timer, and DON'T LEAVE IT! No matter what.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I agree with Rod. If you search RKC REX C100 the manual is freely available. This unit can use a PRT ( a 100Ω ohm at 0°C ) or a thermocouple J or K, BUT you must configure it to work correctly. I use the output to drive a relay. I think the drive is limited to 1A?
It is critical to get the temperature sensor well connected to the heater. I had the physical connection loose about 30° so the blanket went to 180°C instead of 150°C and overheated the blanket. Luckily I saw it and killed the power. You should also fuse the power to the unit.

I use thin probe thermometers (2) as well as the thermocouple in case of some inaccuracy or failure in the PID system.
And the default setting is for a K type.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

That's a very expensive bit of kit you have there. https://www.aliexpress.com/snapshot/818 ... 2623579336

I know, mine cost $20 with SSR, heat sink and thermocouple..........
Works fine so far.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

So, thanks for the help so far. One more :

Now I have the thermocouple but I've found my relay to be quite different from the one Colin mentioned. Any help on wiring this?

Thanks again.

_________________
member of the guild of professional dilettantes

Can't really help except I found this link from make and model number
http://www.tme.eu/en/details/rm84-p-24v/miniature-electromagnetic-relays/relpol/rm84-2012-35-1024/
It appears the relay you have is for mounting in a printed circuit board, and may have been just what he had access to at the time.
It's rated at 8 amps, 240 volts so should be good for up to 1,920 watts maximum - normal blanket maximum is under that, but check.
As to wiring, dont have a clue.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

For most electronic parts you can simply type the part number into Google (RM84-2012-35-5230 in this case) and look for a data sheet. I look for the big distributors first: Digikey, Mouser, Newark, and Allied. In this case Allied sells these and if you go to the part page you will see a link for a PDF data sheet which will tell you everything you need to know about that relay, and a lot you don't care about too. Find the connection diagram for the RM84 series to find out which pins are what.

RM84-2012-35-5230 at Allied: http://www.alliedelec.com/altech-corp-rm84-2012-35-5230/70245611/?mkwid=sZZdjcVZO&pcrid=64705361417&pkw=rm84-2012-35-5230&pmt=e&pdv=c&gclid=CjwKEAjw-abABRDquOTJi8qdojwSJABt1S1O7zY0kEuSSJ6BpExvs9Hi3cqXkgH99-a9XiN7apGJThoCJq_w_wcB

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