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-   -   DIY Kiln Controller (http://www.craftbanter.com/showthread.php?t=114824)

Jules February 16th 11 04:44 PM

DIY Kiln Controller
 
Hi - just wondered if anyone has come across any diy plans for an electric kiln controller using an embedded controller?

I'm in the process of trying to make one, but it would be nice to see some others for comparison.

Regards

Jules

Bob Masta[_2_] February 17th 11 02:26 PM

DIY Kiln Controller
 
On Wed, 16 Feb 2011 15:44:26 +0000, Jules
wrote:


Hi - just wondered if anyone has come across any diy plans for an
electric kiln controller using an embedded controller?

I'm in the process of trying to make one, but it would be nice to see
some others for comparison.


No, but I've thought about it. I was thinking more along
the lines of putting an old PC to use for this, since I have
a bunch on hand, and also I could have it plot out
temperature versus time.

The main drawback for me is that modern Windows PCs have no
easy-to-use I/O (parallel port), and older DOS units would
be more trouble to program... and more pointless, if I
wanted to share the plans with others who were not similarly
endowed with a computer graveyard.

However, I have developed a circuit to use a Windows sound
card to read thermocouples (see
http://www.daqarta.com/dw_kkjj.htm ), and it will probably
be fairly easy to get the sound card output to control the
elements.

Since all this involves circuit contruction, it probably
will appeal only to the most die-hard tinkerers. I think
your idea of using an embedded controller makes a lot more
sense, though.

Best regards,


Bob Masta

DAQARTA v6.00
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
Frequency Counter, FREE Signal Generator
Pitch Track, Pitch-to-MIDI
Science with your sound card!

Jules February 18th 11 10:20 PM

hi Bob thanks for your reply, i know what you mean by old PCs’ seem less hassle to interface than new ones. I was thinking of using a modern PC running some software to monitor the kilns progress etc but the PC would not be allowed to interfere with the kilns operation.

I’ve seen a few examples of people using a pre-built temperature module then adding a thermocouple then just connecting it up to the elements, but I want to control the heat ramp / soaks etc.

Regards

Jules

Jules February 22nd 11 03:41 PM

1 Attachment(s)
Just done some low current switching tests; starting to get there now; still a few more tests / code revisions to make before it's ready to hook up to the kiln elements. I'll probably test by cooking a potato on a custom 3 segment ramp ;-)

Jules March 9th 11 11:03 AM

Quote:

Originally Posted by Jules (Post 876392)
Just done some low current switching tests; starting to get there now; still a few more tests / code revisions to make before it's ready to hook up to the kiln elements. I'll probably test by cooking a potato on a custom 3 segment ramp ;-)

It's been a few days but No I haven't given up;-), still doing tests and code additions / revisions. I want a core set of kiln controller functionality before I set onto a pcb.

The functionality I want is..

(1) 10 internal preset programs (for pottery)
(2) clock set
(3) start delay
(3) set vent
(4) alarm options
(5) power trip restart
(6) firing program logging
(7) ability to upload / download programs / logs to a smartphone / pc software

Bob Masta[_2_] March 9th 11 02:15 PM

DIY Kiln Controller
 
On Wed, 9 Mar 2011 10:03:02 +0000, Jules
wrote:


Jules;876392 Wrote:
Just done some low current switching tests; starting to get there now;
still a few more tests / code revisions to make before it's ready to
hook up to the kiln elements. I'll probably test by cooking a potato on
a custom 3 segment ramp ;-)


It's been a few days but No I haven't given up;-), still doing tests and
code additions / revisions. I want a core set of kiln controller
functionality before I set onto a pcb.

The functionality I want is..

(1) 10 internal preset programs (for pottery)
(2) clock set
(3) start delay
(3) set vent
(4) alarm options
(5) power trip restart
(6) firing program logging
(7) ability to upload / download programs / logs to a smartphone / pc
software


Sounds great! Have you got a thermocouple system worked out
yet? I haven't looked into what's available (or affordable)
off-the-shelf for easy interfacing to a controller.

I suppose if your controller has 2 A/D inputs you could use
one for the TC and one for a reference junction measurement,
and do the corrections in software.

Best regards,


Bob Masta

DAQARTA v6.00
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
Frequency Counter, FREE Signal Generator
Pitch Track, Pitch-to-MIDI
Science with your sound card!

Jules March 9th 11 05:57 PM

Quote:

Sounds great! Have you got a thermocouple system worked out
yet? I haven't looked into what's available (or affordable)
off-the-shelf for easy interfacing to a controller.

I suppose if your controller has 2 A/D inputs you could use
one for the TC and one for a reference junction measurement,
and do the corrections in software.
Yes, I'm using the K-type with the AD595; expensive but less hassle, the Ad595 has it's own cold-point compensation;
I had small problem with noise but I made it stable by filtering it out in software,
hopefully this will remain so when switching the 21 amps on/off.
I also have an offset table for +- adjustment for trimming if required.

I'd like not to use the AD595 as it's quite expensive as chips go; my idea is to use as few components
as possible and make it as cheap as possible.

The interface side i'm not decided yet, after seeing your site I was thinking of using a
simple audio jack to send data back and forth, as even modern computers have them and a audio jack cable is very cheap to buy.

I'm not an electronics engineer so all this is new to me.

Zard March 25th 11 07:59 PM

Jules,
I am also interested in doing this on a old kiln I have with just a kiln setter. I was looking on ebay and found this: "Temperature Controller PID Kiln Ramp Soak 64-Setpoints" which along with this: "SSR25A SOLID STATE RELAY for PID Temperature Controller" might just do the trick. Together they go for around a $100. What do you think?
Zard

Quote:

Originally Posted by Jules (Post 875961)
Hi - just wondered if anyone has come across any diy plans for an electric kiln controller using an embedded controller?

I'm in the process of trying to make one, but it would be nice to see some others for comparison.

Regards

Jules


Jules March 25th 11 09:57 PM

Quote:

Originally Posted by Zard (Post 879023)
Jules,
I am also interested in doing this on a old kiln I have with just a kiln setter. I was looking on ebay and found this: "Temperature Controller PID Kiln Ramp Soak 64-Setpoints" which along with this: "SSR25A SOLID STATE RELAY for PID Temperature Controller" might just do the trick. Together they go for around a $100. What do you think?
Zard

Hi Zard,
I looked into PID units but I personally wanted something
custom for myself. Try and google info on setting these up
or ask someone who has one already setup and running.

My Kiln is an old one that had a kiln sitter. The kiln draws
around 21.8 Amps, i'm using 3 x 80A SSRs mounted on
heatsinks with an old computer fan, so if one fails and locks-on
I always have a backup SSR to turn it all off.

Regards

Jules


ht**://www.tinypixels.co.uk/projects/kiln/index.htm

Jules April 11th 11 03:45 PM

2 Attachment(s)
Tested and works fine :-) I Just need to create the pcb artwork and then put onto a pcb then into a box and make all the kiln connections tidy.

ht**://www.tinypixels.co.uk/projects/kiln/index.htm


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