Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.sys.raspberry-pi > #9539 > unrolled thread

controlling a mains-powered oven

Started byJim Nagel <jimnewsm13c@abbeypress.co.uk>
First post2015-09-06 15:20 +0100
Last post2016-02-21 21:50 +0000
Articles 20 on this page of 90 — 22 participants

Back to article view | Back to comp.sys.raspberry-pi


Contents

  controlling a mains-powered oven Jim Nagel <jimnewsm13c@abbeypress.co.uk> - 2015-09-06 15:20 +0100
    Re: controlling a mains-powered oven "gareth" <no.spam@thank.you.invalid> - 2015-09-06 17:40 +0100
      Re: controlling a mains-powered oven Andy Burns <usenet.feb2014@adslpipe.co.uk> - 2015-09-06 17:56 +0100
        Re: controlling a mains-powered oven The Natural Philosopher <tnp@invalid.invalid> - 2015-09-06 18:40 +0100
          Re: controlling a mains-powered oven Bernard Peek <{bap}@gamma.shrdlu.com> - 2015-09-07 20:16 +0000
    Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-09-06 18:09 +0000
      Re: controlling a mains-powered oven mick <invalid@invalid.invalid> - 2015-09-07 08:03 +0000
      Re: controlling a mains-powered oven Alan Adams <alan@adamshome.org.uk> - 2015-09-07 09:48 +0100
        Re: controlling a mains-powered oven mm0fmf <none@mailinator.com> - 2015-09-07 19:19 +0100
          Re: controlling a mains-powered oven Kallu Wiegand <spam.only@roev.de> - 2015-09-08 21:12 +0200
      Re: controlling a mains-powered oven Jim Nagel <jimnewsm13c@abbeypress.co.uk> - 2015-11-20 14:08 +0000
        Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-11-21 14:23 +0000
          Re: controlling a mains-powered oven Folderol <general@musically.me.uk> - 2015-11-21 14:55 +0000
          Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-11-21 10:50 -0500
            Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-11-21 19:06 +0000
              Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-11-21 20:52 -0500
                Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-11-22 10:11 +0000
                  Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-11-22 10:47 -0500
                    Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-11-22 18:17 +0000
                      Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-11-22 13:51 -0500
                        Re: controlling a mains-powered oven Andy Burns <usenet.feb2014@adslpipe.co.uk> - 2015-11-22 18:59 +0000
                          Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-11-22 14:26 -0500
                            Re: controlling a mains-powered oven Andy Burns <usenet.feb2014@adslpipe.co.uk> - 2015-11-22 19:50 +0000
                              Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-11-22 15:05 -0500
                                Re: controlling a mains-powered oven Andy Burns <usenet.feb2014@adslpipe.co.uk> - 2015-11-22 20:17 +0000
                                  Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-11-22 20:52 +0000
                                    Re: controlling a mains-powered oven Jim Nagel <jimnewsm13c@abbeypress.co.uk> - 2015-11-27 01:06 +0000
                                      Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-11-27 18:15 +0000
                                Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-11-22 20:21 +0000
                                  Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-11-22 15:40 -0500
                                    Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-11-22 20:54 +0000
                                      Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-11-22 16:08 -0500
                                        Re: controlling a mains-powered oven The Natural Philosopher <tnp@invalid.invalid> - 2015-11-23 05:02 +0000
                                      Re: controlling a mains-powered oven Charlie <cdknospam@msn.com> - 2015-12-11 21:27 -0500
                                        Re: controlling a mains-powered oven Theo Markettos <theom+news@chiark.greenend.org.uk> - 2015-12-12 13:53 +0000
                                          Re: controlling a mains-powered oven Charlie <cdknospam@msn.com> - 2015-12-15 22:17 -0500
                                            Re: controlling a mains-powered oven Folderol <general@musically.me.uk> - 2015-12-16 10:01 +0000
                                              Re: controlling a mains-powered oven Charlie <cdknospam@msn.com> - 2015-12-19 19:47 -0500
                                            Re: controlling a mains-powered oven Stuart <Spambin@argonet.co.uk> - 2015-12-20 12:28 +0000
                                              Re: controlling a mains-powered oven Kallu Wiegand <spam.only@roev.de> - 2015-12-20 15:59 +0100
                                                Re: controlling a mains-powered oven Stuart <Spambin@argonet.co.uk> - 2015-12-20 16:26 +0000
                                                  Re: controlling a mains-powered oven Folderol <general@musically.me.uk> - 2015-12-20 17:54 +0000
                                                    Re: controlling a mains-powered oven Kallu Wiegand <spam.only@roev.de> - 2015-12-20 23:21 +0100
                                                      Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-12-21 09:52 +0000
                                                        Re: controlling a mains-powered oven Andy Burns <usenet.feb2014@adslpipe.co.uk> - 2015-12-21 12:30 +0000
                                                          Re: controlling a mains-powered oven The Natural Philosopher <tnp@invalid.invalid> - 2015-12-21 12:39 +0000
                                                        Re: controlling a mains-powered oven Folderol <general@musically.me.uk> - 2015-12-21 18:28 +0000
                                                        Re: controlling a mains-powered oven mm0fmf <none@mailinator.com> - 2015-12-22 08:52 +0000
                                                          Re: controlling a mains-powered oven The Natural Philosopher <tnp@invalid.invalid> - 2015-12-22 08:56 +0000
                                                        Re: controlling a mains-powered oven Charlie <cdknospam@msn.com> - 2015-12-22 10:53 -0500
                                                  Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-12-20 13:18 -0500
                                                    Re: controlling a mains-powered oven Paul <paul@pcserviceselectronics.co.uk> - 2015-12-22 13:44 +0000
                                                      Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-12-22 10:47 -0500
                                                        Re: controlling a mains-powered oven Paul <paul@pcserviceselectronics.co.uk> - 2015-12-22 18:33 +0000
                                                      Re: controlling a mains-powered oven Charlie <cdknospam@msn.com> - 2015-12-22 11:08 -0500
                          Re: controlling a mains-powered oven mm0fmf <none@mailinator.com> - 2015-11-22 19:42 +0000
    Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-09-07 14:25 -0400
    Re: controlling a mains-powered oven Dr J R Stockton <reply1500@merlyn.demon.co.uk.invalid> - 2015-09-07 21:10 +0100
      Re: controlling a mains-powered oven The Natural Philosopher <tnp@invalid.invalid> - 2015-09-07 23:49 +0100
        Re: controlling a mains-powered oven Alan Adams <alan@adamshome.org.uk> - 2015-09-08 09:04 +0100
          Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-09-08 05:32 -0400
            Re: controlling a mains-powered oven Folderol <general@musically.me.uk> - 2015-09-08 18:21 +0100
              Re: controlling a mains-powered oven Jim Nagel <jimnewsm13c@abbeypress.co.uk> - 2015-09-08 19:03 +0100
                Re: controlling a mains-powered oven Folderol <general@musically.me.uk> - 2015-09-08 19:11 +0100
                Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-09-08 14:15 -0400
                Re: controlling a mains-powered oven The Natural Philosopher <tnp@invalid.invalid> - 2015-09-08 22:27 +0100
                Re: controlling a mains-powered oven Theo Markettos <theom+news@chiark.greenend.org.uk> - 2015-09-09 14:05 +0100
                  Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-09-09 13:10 +0000
                    Re: controlling a mains-powered oven Theo Markettos <theom+news@chiark.greenend.org.uk> - 2015-09-09 15:46 +0100
                      Re: controlling a mains-powered oven Rob <nomail@example.com> - 2015-09-09 16:08 +0000
                        Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-09-09 19:14 +0000
                          Re: controlling a mains-powered oven Folderol <general@musically.me.uk> - 2015-09-09 21:00 +0100
                            Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-09-09 21:59 +0000
                          Re: controlling a mains-powered oven Theo Markettos <theom+news@chiark.greenend.org.uk> - 2015-09-09 23:58 +0100
                            Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-09-10 06:17 +0000
                      Re: controlling a mains-powered oven rickman <gnuarm@gmail.com> - 2015-09-09 23:48 -0400
              Re: controlling a mains-powered oven Alan Adams <alan@adamshome.org.uk> - 2015-09-08 19:02 +0100
        Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-09-08 11:23 +0000
          Re: controlling a mains-powered oven mm0fmf <none@mailinator.com> - 2015-09-08 12:41 +0100
          Re: controlling a mains-powered oven Ahem A Rivet's Shot <steveo@eircom.net> - 2015-09-08 12:58 +0100
            Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-09-08 13:26 +0000
              Re: controlling a mains-powered oven Ahem A Rivet's Shot <steveo@eircom.net> - 2015-09-08 14:50 +0100
                Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-09-08 14:24 +0000
                  Re: controlling a mains-powered oven "A. Dumas" <alexandre@dumas.fr.invalid> - 2015-09-08 17:17 +0200
        Re: controlling a mains-powered oven Dr J R Stockton <reply1500@merlyn.demon.co.uk.invalid> - 2015-09-08 22:05 +0100
    Re: controlling a mains-powered oven Gordon Henderson <gordon+usenet@drogon.net> - 2015-12-20 10:15 +0000
    Re: controlling a mains-powered oven David <wibble@btintenet.com> - 2016-02-20 14:37 +0000
      Re: controlling a mains-powered oven Rob Morley <nospam@ntlworld.com> - 2016-02-20 14:53 +0000
      Re: controlling a mains-powered oven David <wibble@btintenet.com> - 2016-02-20 16:33 +0000
        Re: controlling a mains-powered oven Paul <paul@pcserviceselectronics.co.uk> - 2016-02-21 21:50 +0000

Page 2 of 5 — ← Prev page 1 [2] 3 4 5  Next page →


#10002

FromAndy Burns <usenet.feb2014@adslpipe.co.uk>
Date2015-11-22 18:59 +0000
Message-ID<rqmdnUfaE5c5jc_LnZ2dnUU78X2dnZ2d@brightview.co.uk>
In reply to#10001
rickman wrote:

> Gordon Henderson wrote:
 >
>>>>>> I'm only sampling the data every second - the PID control loop is running
>>>>>> 10 times/sec.
>>>>>
>>>>> I'm not sure why you would run the two at different rates.  Do you know
>>>>> why?
>>>>
>>>> Yes. I wrote the program, so I know exactly why.
>>>
>>> Can you explain?
>>
>> Yes.
>
> Ok

I suggest if you'd had less of the "aggressive know-all" attitude, he 
might have done so ...

[toc] | [prev] | [next] | [standalone]


#10003

Fromrickman <gnuarm@gmail.com>
Date2015-11-22 14:26 -0500
Message-ID<n2t4o4$91u$5@dont-email.me>
In reply to#10002
On 11/22/2015 1:59 PM, Andy Burns wrote:
> rickman wrote:
>
>> Gordon Henderson wrote:
>  >
>>>>>>> I'm only sampling the data every second - the PID control loop is
>>>>>>> running
>>>>>>> 10 times/sec.
>>>>>>
>>>>>> I'm not sure why you would run the two at different rates.  Do you
>>>>>> know
>>>>>> why?
>>>>>
>>>>> Yes. I wrote the program, so I know exactly why.
>>>>
>>>> Can you explain?
>>>
>>> Yes.
>>
>> Ok
>
> I suggest if you'd had less of the "aggressive know-all" attitude, he
> might have done so ...

Asking questions is "aggressive"?

-- 

Rick

[toc] | [prev] | [next] | [standalone]


#10006

FromAndy Burns <usenet.feb2014@adslpipe.co.uk>
Date2015-11-22 19:50 +0000
Message-ID<1YOdnX3Ab4cLgc_LnZ2dnUU78VmdnZ2d@brightview.co.uk>
In reply to#10003
rickman wrote:

> Asking questions is "aggressive"?

That's how the tone felt, to me at least ...

[toc] | [prev] | [next] | [standalone]


#10007

Fromrickman <gnuarm@gmail.com>
Date2015-11-22 15:05 -0500
Message-ID<n2t72e$ko2$1@dont-email.me>
In reply to#10006
On 11/22/2015 2:50 PM, Andy Burns wrote:
> rickman wrote:
>
>> Asking questions is "aggressive"?
>
> That's how the tone felt, to me at least ...

I'm sorry about the tone.   I'm trying to understand what the OP was 
trying to do, or more specifically what he though the PID controller 
would do for him.  Not trying to be rude or ruffle anyone's feathers.

Printed words can come across very differently than when spoken.  I 
don't always perceive the tone others do.  Sorry.

-- 

Rick

[toc] | [prev] | [next] | [standalone]


#10008

FromAndy Burns <usenet.feb2014@adslpipe.co.uk>
Date2015-11-22 20:17 +0000
Message-ID<QeGdnZz3y_Yhv8_LnZ2dnUU78YWdnZ2d@brightview.co.uk>
In reply to#10007
rickman wrote:

> Printed words can come across very differently than when spoken.  I
> don't always perceive the tone others do.  Sorry.

Yeah, that can happen, hopefully Gordon will return and give us some 
details after all ...


[toc] | [prev] | [next] | [standalone]


#10011

FromGordon Henderson <gordon+usenet@drogon.net>
Date2015-11-22 20:52 +0000
Message-ID<n2t9v0$1lv$1@dont-email.me>
In reply to#10008
In article <QeGdnZz3y_Yhv8_LnZ2dnUU78YWdnZ2d@brightview.co.uk>,
Andy Burns  <usenet.feb2014@adslpipe.co.uk> wrote:
>rickman wrote:
>
>> Printed words can come across very differently than when spoken.  I
>> don't always perceive the tone others do.  Sorry.
>
>Yeah, that can happen, hopefully Gordon will return and give us some 
>details after all ...

Details, details, details... It's all in the detail...

Now where were we... The program is multi-threaded. One thread reads
the thermistors and provides a single temperature reading to the rest of
the system. It also provides a means to get te 'raw' temperatures. This
happens to be sampling the thermistors some 50 times/sec. There's a
low-pass filter in there and code to check if any thermistor gets too
far from the others.  There is also optional "voting logic" code in
there (to use 2 out of 3 thermistors), but it's not that good in this
application. Just because I can more than anything else.

Another thread is the PID controller. This happens to run at 10Hz -
mostly because I don't want to cycle the power more than 10 times/sec
and the power control comes from the PID loop. I /could/ use a crude PWM
on the power by running another thread to do that, but I don't feel its
worth it. For now.

Yet another thread logs the data to a file. This thread only runs once
a second. I have enough data as it is without looking for more. Hobby
project and all that, you know?

Right now it's a small C program, command-line driven. I want to re-code
it in my BASIC so I can have a nice display and control widgets on a
little 5" HDMI display and touchscreen thingy I have, but hobby project
and all that... Besides, RTB doesn't support threads yet, but co-routines
are on the horizon...

So all in all, to go back to the original author of this thread; Yes,
controling a domestic oven with a Pi is fesable. Relatively economical
too - well. FSVO... Under £100 will get you a Pi, one thermistor +
amp breakout board, an SSR, PSU and Wi-Fi dongle. (I recall the OP was
looking at £200 for a new controller - more than the cost of my oven!)

Gordon

[toc] | [prev] | [next] | [standalone]


#10026

FromJim Nagel <jimnewsm13c@abbeypress.co.uk>
Date2015-11-27 01:06 +0000
Message-ID<9bd0d82855.jim@abbeypress.net>
In reply to#10011
Gordon Henderson  wrote on 22 Nov:
> ... So all in all, to go back to the original author of this thread;
> Yes, controling a domestic oven with a Pi is fesable. Relatively
> economical too - well. FSVO... Under £100 will get you a Pi, one
> thermistor + amp breakout board, an SSR, PSU and Wi-Fi dongle. (I
> recall the OP was looking at £200 for a new controller - more than the
> cost of my oven!)

That was me.  Thanks for all that experience.  Current state of play 
here is:
   (a) wife wants an oven she can depend on for Christmas; her 
campaign to scrap the oven and buy a new one is heating up
   (b) I'm looking at existing oven's relays and thermo-probes, 
considering what components I can retain to be controlled by a Pi.  
Managed to get a wiring diagram today from the manufacturer (which is 
De Dietrich, whose UK affiliate went bust a year or two ago; I learned 
today that a new UK distributor stepped in only recently).


-- 
Jim Nagel                        www.archivemag.co.uk
>> "from" address is genuine but will change.  website has current one.

[toc] | [prev] | [next] | [standalone]


#10030

FromGordon Henderson <gordon+usenet@drogon.net>
Date2015-11-27 18:15 +0000
Message-ID<n3a6jd$crk$1@dont-email.me>
In reply to#10026
In article <9bd0d82855.jim@abbeypress.net>,
Jim Nagel  <jimnewsm13c@abbeypress.co.uk> wrote:
>Gordon Henderson  wrote on 22 Nov:
>> ... So all in all, to go back to the original author of this thread;
>> Yes, controling a domestic oven with a Pi is fesable. Relatively
>> economical too - well. FSVO... Under Ł100 will get you a Pi, one
>> thermistor + amp breakout board, an SSR, PSU and Wi-Fi dongle. (I
>> recall the OP was looking at Ł200 for a new controller - more than the
>> cost of my oven!)
>
>That was me.  Thanks for all that experience.  Current state of play 
>here is:
>   (a) wife wants an oven she can depend on for Christmas; her 
>campaign to scrap the oven and buy a new one is heating up
>   (b) I'm looking at existing oven's relays and thermo-probes, 
>considering what components I can retain to be controlled by a Pi.  
>Managed to get a wiring diagram today from the manufacturer (which is 
>De Dietrich, whose UK affiliate went bust a year or two ago; I learned 
>today that a new UK distributor stepped in only recently).

I found my cheap oven very easy to take to bits to check stuff, etc. As it
was very mechanical, it was easy to trace all the wires and work out what
was doing what. In the end, I simply wired the SSR over the 2 terminals
going into the rotary thermostat thingy, so to run it with the Pi, I
leave the dial set to zero but turn on the main power and oven selector,
or just use the temperature dial to run it in the old way.

Also, the main power knob is the mechanical timer knob - one hour max, so
I just wind that up, then if something does go wrong, at least it will
turn itself off after an hour.

For your oven - if it's a capiliary tube system, you might get away with
bypassing the existing controller by simply buying a replacement tube +
thermostat dial for another oven and wiring it in. It was about Ł14 for
the one on my Beko when I replaced it last year.

However, here's a suggestion - scrap the oven and replace it with a really
cheap one - my Beko cost Ł195 and is OK - no frills, nothing digital and
has done me well for the past 2+ years baking breads at 250°C ...

Then use the old one as a test-bed to play with, then retro fit the controller
to the new oven (or swap them back) when you have Pi control :-)

Good luck!

Gordon

[toc] | [prev] | [next] | [standalone]


#10009

FromGordon Henderson <gordon+usenet@drogon.net>
Date2015-11-22 20:21 +0000
Message-ID<n2t848$nf7$1@dont-email.me>
In reply to#10007
In article <n2t72e$ko2$1@dont-email.me>, rickman  <gnuarm@gmail.com> wrote:
>On 11/22/2015 2:50 PM, Andy Burns wrote:
>> rickman wrote:
>>
>>> Asking questions is "aggressive"?
>>
>> That's how the tone felt, to me at least ...
>
>I'm sorry about the tone.   I'm trying to understand what the OP was 
>trying to do, or more specifically what he though the PID controller 
>would do for him.  Not trying to be rude or ruffle anyone's feathers.

I've already told you why I'm using PID. It's because I can. Because it's
there, and why not. Also consider this: Because it's fun. I do this for
fun - I've spent over 30 years doing it for money and now I want some fun.

I also want good cakes and bread. Which I sell. For money.

Sourdough honey spelt, anyone?

http://unicorn.drogon.net/honeySpelt2.jpg

Gordon

[toc] | [prev] | [next] | [standalone]


#10010

Fromrickman <gnuarm@gmail.com>
Date2015-11-22 15:40 -0500
Message-ID<n2t94d$sob$2@dont-email.me>
In reply to#10009
On 11/22/2015 3:21 PM, Gordon Henderson wrote:
> In article <n2t72e$ko2$1@dont-email.me>, rickman  <gnuarm@gmail.com> wrote:
>> On 11/22/2015 2:50 PM, Andy Burns wrote:
>>> rickman wrote:
>>>
>>>> Asking questions is "aggressive"?
>>>
>>> That's how the tone felt, to me at least ...
>>
>> I'm sorry about the tone.   I'm trying to understand what the OP was
>> trying to do, or more specifically what he though the PID controller
>> would do for him.  Not trying to be rude or ruffle anyone's feathers.
>
> I've already told you why I'm using PID. It's because I can. Because it's
> there, and why not. Also consider this: Because it's fun. I do this for
> fun - I've spent over 30 years doing it for money and now I want some fun.
>
> I also want good cakes and bread. Which I sell. For money.

Ok, so the PID is for fun.  I get that I suppose.  But you talk about 
trying to improve it and I don't get that when I expect it would work 
better with a simpler thermostat type controller.  If you don't believe 
that is the case I would be interested in discussing it.  If you just 
want to improve the PID controller for the fun of it, I guess I get that 
too.  I'm thinking of building a high accuracy clock and not because I 
want to know what time it is.

-- 

Rick

[toc] | [prev] | [next] | [standalone]


#10012

FromGordon Henderson <gordon+usenet@drogon.net>
Date2015-11-22 20:54 +0000
Message-ID<n2ta2o$1lv$2@dont-email.me>
In reply to#10010
In article <n2t94d$sob$2@dont-email.me>, rickman  <gnuarm@gmail.com> wrote:
>On 11/22/2015 3:21 PM, Gordon Henderson wrote:
>> In article <n2t72e$ko2$1@dont-email.me>, rickman  <gnuarm@gmail.com> wrote:
>>> On 11/22/2015 2:50 PM, Andy Burns wrote:
>>>> rickman wrote:
>>>>
>>>>> Asking questions is "aggressive"?
>>>>
>>>> That's how the tone felt, to me at least ...
>>>
>>> I'm sorry about the tone.   I'm trying to understand what the OP was
>>> trying to do, or more specifically what he though the PID controller
>>> would do for him.  Not trying to be rude or ruffle anyone's feathers.
>>
>> I've already told you why I'm using PID. It's because I can. Because it's
>> there, and why not. Also consider this: Because it's fun. I do this for
>> fun - I've spent over 30 years doing it for money and now I want some fun.
>>
>> I also want good cakes and bread. Which I sell. For money.
>
>Ok, so the PID is for fun.  I get that I suppose.  But you talk about 
>trying to improve it and I don't get that when I expect it would work 
>better with a simpler thermostat type controller.  If you don't believe 
>that is the case I would be interested in discussing it.  If you just 
>want to improve the PID controller for the fun of it, I guess I get that 
>too.  I'm thinking of building a high accuracy clock and not because I 
>want to know what time it is.

I have a Pi connected to a radioclock:

gordon @ pi0: ntpq
ntpq> rl
associd=0 status=0415 leap_none, sync_uhf_radio, 1 event, clock_sync,
version="ntpd 4.2.6p5@1.2349-o Fri May 18 20:30:57 UTC 2012 (1)",
processor="armv6l", system="Linux/3.12.29+", leap=00, stratum=1,
precision=-20, rootdelay=0.000, rootdisp=4.322, refid=MSF,
reftime=d9fcaa51.307ec454  Sun, Nov 22 2015 20:55:45.189,
clock=d9fcaa6f.640c49cc  Sun, Nov 22 2015 20:56:15.390, peer=3803, tc=6,
mintc=3, offset=-0.437, frequency=-47.665, sys_jitter=2.646,
clk_jitter=0.570, clk_wander=0.029

Good enough for me.

Gordon

[toc] | [prev] | [next] | [standalone]


#10013

Fromrickman <gnuarm@gmail.com>
Date2015-11-22 16:08 -0500
Message-ID<n2taor$4qv$1@dont-email.me>
In reply to#10012
On 11/22/2015 3:54 PM, Gordon Henderson wrote:
> In article <n2t94d$sob$2@dont-email.me>, rickman  <gnuarm@gmail.com> wrote:
>> On 11/22/2015 3:21 PM, Gordon Henderson wrote:
>>> In article <n2t72e$ko2$1@dont-email.me>, rickman  <gnuarm@gmail.com> wrote:
>>>> On 11/22/2015 2:50 PM, Andy Burns wrote:
>>>>> rickman wrote:
>>>>>
>>>>>> Asking questions is "aggressive"?
>>>>>
>>>>> That's how the tone felt, to me at least ...
>>>>
>>>> I'm sorry about the tone.   I'm trying to understand what the OP was
>>>> trying to do, or more specifically what he though the PID controller
>>>> would do for him.  Not trying to be rude or ruffle anyone's feathers.
>>>
>>> I've already told you why I'm using PID. It's because I can. Because it's
>>> there, and why not. Also consider this: Because it's fun. I do this for
>>> fun - I've spent over 30 years doing it for money and now I want some fun.
>>>
>>> I also want good cakes and bread. Which I sell. For money.
>>
>> Ok, so the PID is for fun.  I get that I suppose.  But you talk about
>> trying to improve it and I don't get that when I expect it would work
>> better with a simpler thermostat type controller.  If you don't believe
>> that is the case I would be interested in discussing it.  If you just
>> want to improve the PID controller for the fun of it, I guess I get that
>> too.  I'm thinking of building a high accuracy clock and not because I
>> want to know what time it is.
>
> I have a Pi connected to a radioclock:
>
> gordon @ pi0: ntpq
> ntpq> rl
> associd=0 status=0415 leap_none, sync_uhf_radio, 1 event, clock_sync,
> version="ntpd 4.2.6p5@1.2349-o Fri May 18 20:30:57 UTC 2012 (1)",
> processor="armv6l", system="Linux/3.12.29+", leap=00, stratum=1,
> precision=-20, rootdelay=0.000, rootdisp=4.322, refid=MSF,
> reftime=d9fcaa51.307ec454  Sun, Nov 22 2015 20:55:45.189,
> clock=d9fcaa6f.640c49cc  Sun, Nov 22 2015 20:56:15.390, peer=3803, tc=6,
> mintc=3, offset=-0.437, frequency=-47.665, sys_jitter=2.646,
> clk_jitter=0.570, clk_wander=0.029
>
> Good enough for me.

I mean a mechanical clock.  There are mechanical clocks that run more 
accurately than the typical digital watch.

-- 

Rick

[toc] | [prev] | [next] | [standalone]


#10014

FromThe Natural Philosopher <tnp@invalid.invalid>
Date2015-11-23 05:02 +0000
Message-ID<n2u6lr$8i1$4@news.albasani.net>
In reply to#10013
On 22/11/15 21:08, rickman wrote:
> On 11/22/2015 3:54 PM, Gordon Henderson wrote:
>> In article <n2t94d$sob$2@dont-email.me>, rickman  <gnuarm@gmail.com>
>> wrote:
>>> On 11/22/2015 3:21 PM, Gordon Henderson wrote:
>>>> In article <n2t72e$ko2$1@dont-email.me>, rickman  <gnuarm@gmail.com>
>>>> wrote:
>>>>> On 11/22/2015 2:50 PM, Andy Burns wrote:
>>>>>> rickman wrote:
>>>>>>
>>>>>>> Asking questions is "aggressive"?
>>>>>>
>>>>>> That's how the tone felt, to me at least ...
>>>>>
>>>>> I'm sorry about the tone.   I'm trying to understand what the OP was
>>>>> trying to do, or more specifically what he though the PID controller
>>>>> would do for him.  Not trying to be rude or ruffle anyone's feathers.
>>>>
>>>> I've already told you why I'm using PID. It's because I can. Because
>>>> it's
>>>> there, and why not. Also consider this: Because it's fun. I do this for
>>>> fun - I've spent over 30 years doing it for money and now I want
>>>> some fun.
>>>>
>>>> I also want good cakes and bread. Which I sell. For money.
>>>
>>> Ok, so the PID is for fun.  I get that I suppose.  But you talk about
>>> trying to improve it and I don't get that when I expect it would work
>>> better with a simpler thermostat type controller.  If you don't believe
>>> that is the case I would be interested in discussing it.  If you just
>>> want to improve the PID controller for the fun of it, I guess I get that
>>> too.  I'm thinking of building a high accuracy clock and not because I
>>> want to know what time it is.
>>
>> I have a Pi connected to a radioclock:
>>
>> gordon @ pi0: ntpq
>> ntpq> rl
>> associd=0 status=0415 leap_none, sync_uhf_radio, 1 event, clock_sync,
>> version="ntpd 4.2.6p5@1.2349-o Fri May 18 20:30:57 UTC 2012 (1)",
>> processor="armv6l", system="Linux/3.12.29+", leap=00, stratum=1,
>> precision=-20, rootdelay=0.000, rootdisp=4.322, refid=MSF,
>> reftime=d9fcaa51.307ec454  Sun, Nov 22 2015 20:55:45.189,
>> clock=d9fcaa6f.640c49cc  Sun, Nov 22 2015 20:56:15.390, peer=3803, tc=6,
>> mintc=3, offset=-0.437, frequency=-47.665, sys_jitter=2.646,
>> clk_jitter=0.570, clk_wander=0.029
>>
>> Good enough for me.
>
> I mean a mechanical clock.  There are mechanical clocks that run more
> accurately than the typical digital watch.
>
That has a mechanical crystal inside it.



-- 
the biggest threat to humanity comes from socialism, which has utterly 
diverted our attention away from what really matters to our existential 
survival, to indulging in navel gazing and faux moral investigations 
into what the world ought to be, whilst we fail utterly to deal with 
what it actually is.

[toc] | [prev] | [next] | [standalone]


#10098

FromCharlie <cdknospam@msn.com>
Date2015-12-11 21:27 -0500
Message-ID<0CLay.46526$051.33662@fx28.iad>
In reply to#10012
On 11/22/2015 3:54 PM, Gordon Henderson wrote:
> In article <n2t94d$sob$2@dont-email.me>, rickman  <gnuarm@gmail.com> wrote:
>> On 11/22/2015 3:21 PM, Gordon Henderson wrote:
>>> In article <n2t72e$ko2$1@dont-email.me>, rickman  <gnuarm@gmail.com> wrote:
>>>> On 11/22/2015 2:50 PM, Andy Burns wrote:
>>>>> rickman wrote:
>>>>>
>>>>>> Asking questions is "aggressive"?
>>>>>
>>>>> That's how the tone felt, to me at least ...
>>>>
>>>> I'm sorry about the tone.   I'm trying to understand what the OP was
>>>> trying to do, or more specifically what he though the PID controller
>>>> would do for him.  Not trying to be rude or ruffle anyone's feathers.
>>>
>>> I've already told you why I'm using PID. It's because I can. Because it's
>>> there, and why not. Also consider this: Because it's fun. I do this for
>>> fun - I've spent over 30 years doing it for money and now I want some fun.
>>>
>>> I also want good cakes and bread. Which I sell. For money.
>>
>> Ok, so the PID is for fun.  I get that I suppose.  But you talk about
>> trying to improve it and I don't get that when I expect it would work
>> better with a simpler thermostat type controller.  If you don't believe
>> that is the case I would be interested in discussing it.  If you just
>> want to improve the PID controller for the fun of it, I guess I get that
>> too.  I'm thinking of building a high accuracy clock and not because I
>> want to know what time it is.
>
> I have a Pi connected to a radioclock:
>
> gordon @ pi0: ntpq
> ntpq> rl
> associd=0 status=0415 leap_none, sync_uhf_radio, 1 event, clock_sync,
> version="ntpd 4.2.6p5@1.2349-o Fri May 18 20:30:57 UTC 2012 (1)",
> processor="armv6l", system="Linux/3.12.29+", leap=00, stratum=1,
> precision=-20, rootdelay=0.000, rootdisp=4.322, refid=MSF,
> reftime=d9fcaa51.307ec454  Sun, Nov 22 2015 20:55:45.189,
> clock=d9fcaa6f.640c49cc  Sun, Nov 22 2015 20:56:15.390, peer=3803, tc=6,
> mintc=3, offset=-0.437, frequency=-47.665, sys_jitter=2.646,
> clk_jitter=0.570, clk_wander=0.029
>
> Good enough for me.
>
> Gordon
>
I applaud your ingenuity.
That said, if I had to do such a thing, I'd likely just order an 
industrial panel unit that measures temperature and contains enough 
"stuff" to control such things as ovens and heaters.
In my long ago working days as as a QC instrument and electronics tech,
when I ran out of more useful things to do, I'd end up calibrating 
temperature controllers for molds, ovens, and so forth. The control 
units always impressed me as to the accuracy and durability.Today,
with oven resistive elements, and high capacity MOSFETS I'd likely 
consider a PWM controller. EMI might be a problem to consider as well.
Solid state switches could also be used, and should be the zero crossing 
type.

[toc] | [prev] | [next] | [standalone]


#10100

FromTheo Markettos <theom+news@chiark.greenend.org.uk>
Date2015-12-12 13:53 +0000
Message-ID<9kg*YMWMv@news.chiark.greenend.org.uk>
In reply to#10098
Charlie <cdknospam@msn.com> wrote:
> I applaud your ingenuity.
> That said, if I had to do such a thing, I'd likely just order an 
> industrial panel unit that measures temperature and contains enough 
> "stuff" to control such things as ovens and heaters.

FWIW we just bought one of these:
http://www.beta-estore.com/rkuk/order_product_details.html?wg=1&p=242
which they also sell with a cheap oven:
http://www.beta-estore.com/rkuk/order_product_details.html?wg=1&p=16

We haven't had a chance to get the hang of it yet, but since everything is
sold as a kit it seems to work together reasonably well.  This is for
soldering rather than baking, but the same principle holds.  The EUR119 for
the controller is less time, hassle and risk of blowing things up than
trying to make one ourselves.

The controller output won't do more than 1.5kW, but secondary switching
(eg a mains relay) should handle that.

Theo

[toc] | [prev] | [next] | [standalone]


#10146

FromCharlie <cdknospam@msn.com>
Date2015-12-15 22:17 -0500
Message-ID<_I4cy.38$xz4.32@fx12.iad>
In reply to#10100
On 12/12/2015 8:53 AM, Theo Markettos wrote:
> Charlie <cdknospam@msn.com> wrote:
>> I applaud your ingenuity.
>> That said, if I had to do such a thing, I'd likely just order an
>> industrial panel unit that measures temperature and contains enough
>> "stuff" to control such things as ovens and heaters.
>
> FWIW we just bought one of these:
> http://www.beta-estore.com/rkuk/order_product_details.html?wg=1&p=242
> which they also sell with a cheap oven:
> http://www.beta-estore.com/rkuk/order_product_details.html?wg=1&p=16
>
> We haven't had a chance to get the hang of it yet, but since everything is
> sold as a kit it seems to work together reasonably well.  This is for
> soldering rather than baking, but the same principle holds.  The EUR119 for
> the controller is less time, hassle and risk of blowing things up than
> trying to make one ourselves.
>
> The controller output won't do more than 1.5kW, but secondary switching
> (eg a mains relay) should handle that.
>
> Theo
>
I'd be tempted to use any conventional oven temperature control present 
as a backup do not go above temperature setting. Relay contacts have 
been known to occasionally fail closed. If I remember correctly, 50hz is 
harder on contacts than 60hz.

[toc] | [prev] | [next] | [standalone]


#10149

FromFolderol <general@musically.me.uk>
Date2015-12-16 10:01 +0000
Message-ID<20151216100107.43ccfde2@debian>
In reply to#10146
On Tue, 15 Dec 2015 22:17:16 -0500
Charlie <cdknospam@msn.com> wrote:

> On 12/12/2015 8:53 AM, Theo Markettos wrote:
> > Charlie <cdknospam@msn.com> wrote:
> >> I applaud your ingenuity.
> >> That said, if I had to do such a thing, I'd likely just order an
> >> industrial panel unit that measures temperature and contains enough
> >> "stuff" to control such things as ovens and heaters.
> >
> > FWIW we just bought one of these:
> > http://www.beta-estore.com/rkuk/order_product_details.html?wg=1&p=242
> > which they also sell with a cheap oven:
> > http://www.beta-estore.com/rkuk/order_product_details.html?wg=1&p=16
> >
> > We haven't had a chance to get the hang of it yet, but since everything is
> > sold as a kit it seems to work together reasonably well.  This is for
> > soldering rather than baking, but the same principle holds.  The EUR119 for
> > the controller is less time, hassle and risk of blowing things up than
> > trying to make one ourselves.
> >
> > The controller output won't do more than 1.5kW, but secondary switching
> > (eg a mains relay) should handle that.
> >
> > Theo
> >
> I'd be tempted to use any conventional oven temperature control present 
> as a backup do not go above temperature setting. Relay contacts have 
> been known to occasionally fail closed. If I remember correctly, 50hz is 
> harder on contacts than 60hz.
> 
> 
It becomes a matter of how far do you go? There is *no* kind of disconnector
that can't fail with the contacts fused, but in over 50 years
industrial experience I've only come across it once, and that was because a
fire in the cabinet warped the plastic housing.

-- 
W J G

[toc] | [prev] | [next] | [standalone]


#10159

FromCharlie <cdknospam@msn.com>
Date2015-12-19 19:47 -0500
Message-ID<5Umdy.1851$m53.713@fx33.iad>
In reply to#10149
On 12/16/2015 5:01 AM, Folderol wrote:
> On Tue, 15 Dec 2015 22:17:16 -0500
> Charlie <cdknospam@msn.com> wrote:
>
>> On 12/12/2015 8:53 AM, Theo Markettos wrote:
>>> Charlie <cdknospam@msn.com> wrote:
>>>> I applaud your ingenuity.
>>>> That said, if I had to do such a thing, I'd likely just order an
>>>> industrial panel unit that measures temperature and contains enough
>>>> "stuff" to control such things as ovens and heaters.
>>>
>>> FWIW we just bought one of these:
>>> http://www.beta-estore.com/rkuk/order_product_details.html?wg=1&p=242
>>> which they also sell with a cheap oven:
>>> http://www.beta-estore.com/rkuk/order_product_details.html?wg=1&p=16
>>>
>>> We haven't had a chance to get the hang of it yet, but since everything is
>>> sold as a kit it seems to work together reasonably well.  This is for
>>> soldering rather than baking, but the same principle holds.  The EUR119 for
>>> the controller is less time, hassle and risk of blowing things up than
>>> trying to make one ourselves.
>>>
>>> The controller output won't do more than 1.5kW, but secondary switching
>>> (eg a mains relay) should handle that.
>>>
>>> Theo
>>>
>> I'd be tempted to use any conventional oven temperature control present
>> as a backup do not go above temperature setting. Relay contacts have
>> been known to occasionally fail closed. If I remember correctly, 50hz is
>> harder on contacts than 60hz.
>>
>>
> It becomes a matter of how far do you go? There is *no* kind of disconnector
> that can't fail with the contacts fused, but in over 50 years
> industrial experience I've only come across it once, and that was because a
> fire in the cabinet warped the plastic housing.
>
  It becomes a matter of how far do you go?
True, so true!

But, with electric Dryers and Ovens, at least in the US there often is a 
high temp cutout. Gas Ovens may or may not also have one. We had an 
older name brand gas oven melt the pot metal gears in the built-in 
rotisserie. Seems that the electrically operated gas valve stuck open.
I ended up doing something that you supposedly are not to do, and 
repaired the valve. In the US the classic gas valve relies on a spring 
to close. Eventually, the spring weakens slightly, and stuff from the 
gas builds up, causing the valve to stick. An old gas company repairman 
(From the days when the gas company provided free repair) showed me how.

The industrial gas and electric ovens we used in the 70's had a safety 
temp sensor and lockout. If it tripped, you found out why, fixed the 
problem, and reset the trip.

One area I had nothing to do with by choice was aluminum casting. They 
melted aluminum and cast the air tight explosion proof containers used 
for oil well switch and motor control gear.

[toc] | [prev] | [next] | [standalone]


#10161

FromStuart <Spambin@argonet.co.uk>
Date2015-12-20 12:28 +0000
Message-ID<5534ef7698Spambin@argonet.co.uk>
In reply to#10146
In article <_I4cy.38$xz4.32@fx12.iad>,
   Charlie <cdknospam@msn.com> wrote:
> I'd be tempted to use any conventional oven temperature control present 
> as a backup do not go above temperature setting. Relay contacts have 
> been known to occasionally fail closed. If I remember correctly, 50hz is 
> harder on contacts than 60hz.

Have you considered that if, you are controlling it electronically, with
care, thought and some careful timing, it ought to be possible to arrange
the relay contacts to open at a zero crossing?

-- 
Stuart Winsor

Tools With A Mission
sending tools across the world
http://www.twam.co.uk/

[toc] | [prev] | [next] | [standalone]


#10162

FromKallu Wiegand <spam.only@roev.de>
Date2015-12-20 15:59 +0100
Message-ID<ddnu50F3r0tU1@mid.individual.net>
In reply to#10161
Am 20.12.2015 um 13:28 Stuart wrote:
> In article <_I4cy.38$xz4.32@fx12.iad>,
>     Charlie <cdknospam@msn.com> wrote:
>> I'd be tempted to use any conventional oven temperature control present
>> as a backup do not go above temperature setting. Relay contacts have
>> been known to occasionally fail closed. If I remember correctly, 50hz is
>> harder on contacts than 60hz.
>
> Have you considered that if, you are controlling it electronically, with
> care, thought and some careful timing, it ought to be possible to arrange
> the relay contacts to open at a zero crossing?

Never with a mechanical contact. Even if you grab the right time for the 
cut (only by chance!), the distance between the opening contacts will 
raise slower than the voltage, causing a nice flashover.

My suggestion would be a Solid-State-Relais.

For maximum security you have to backup the installation with a mains 
relais controlled by and only by a thermo-switch opening by overheating 
in the oven. If this relais is allways closed befor the oven is started 
and normallly only opens after shuting down the oven, it will work its 
contacts with no load and deliver a maximum lifetime.

-- 
Have a nice day!

Kallu

[toc] | [prev] | [next] | [standalone]


Page 2 of 5 — ← Prev page 1 [2] 3 4 5  Next page →

Back to top | Article view | comp.sys.raspberry-pi


csiph-web