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Slightly OT: Wine fridge temperature hysteresis?

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  Slightly OT: Wine fridge temperature hysteresis? Joerg <news@analogconsultants.com> - 2017-03-05 11:31 -0800
    Re: Slightly OT: Wine fridge temperature hysteresis? Adrian Jansen <adrian@qq.vv.net> - 2017-03-06 07:46 +1000
      Re: Slightly OT: Wine fridge temperature hysteresis? Joerg <news@analogconsultants.com> - 2017-03-05 14:43 -0800
        Re: Slightly OT: Wine fridge temperature hysteresis? Adrian Jansen <adrian@qq.vv.net> - 2017-03-06 11:23 +1000
          Re: Slightly OT: Wine fridge temperature hysteresis? Joerg <news@analogconsultants.com> - 2017-03-06 07:48 -0800
        Re: Slightly OT: Wine fridge temperature hysteresis? dplatt@coop.radagast.org (Dave Platt) - 2017-03-06 11:41 -0800
          Re: Slightly OT: Wine fridge temperature hysteresis? Joerg <news@analogconsultants.com> - 2017-03-06 12:04 -0800
    Re: Slightly OT: Wine fridge temperature hysteresis? Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-03-05 14:52 -0800
      Re: Slightly OT: Wine fridge temperature hysteresis? Joerg <news@analogconsultants.com> - 2017-03-05 15:43 -0800
        Re: Slightly OT: Wine fridge temperature hysteresis? Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-03-05 16:15 -0800
          Re: Slightly OT: Wine fridge temperature hysteresis? Joerg <news@analogconsultants.com> - 2017-03-06 07:49 -0800
        Re: Slightly OT: Wine fridge temperature hysteresis? "dcaster@krl.org" <dcaster@krl.org> - 2017-03-05 17:10 -0800
          Re: Slightly OT: Wine fridge temperature hysteresis? amdx <nojunk@knology.net> - 2017-03-06 06:14 -0600
            Re: Slightly OT: Wine fridge temperature hysteresis? makolber@yahoo.com - 2017-03-06 07:18 -0800
            Re: Slightly OT: Wine fridge temperature hysteresis? Joerg <news@analogconsultants.com> - 2017-03-06 07:53 -0800
      Re: Slightly OT: Wine fridge temperature hysteresis? jurb6006@gmail.com - 2017-03-05 16:26 -0800
        Re: Slightly OT: Wine fridge temperature hysteresis? Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-03-05 16:42 -0800
          Re: Slightly OT: Wine fridge temperature hysteresis? jurb6006@gmail.com - 2017-03-05 20:41 -0800
    Re: Slightly OT: Wine fridge temperature hysteresis? Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-03-05 17:53 -0700
      Re: Slightly OT: Wine fridge temperature hysteresis? Joerg <news@analogconsultants.com> - 2017-03-06 08:02 -0800
        Re: Slightly OT: Wine fridge temperature hysteresis? Joerg <news@analogconsultants.com> - 2017-03-06 10:19 -0800
    Re: Slightly OT: Wine fridge temperature hysteresis? Mike Perkins <spam@spam.com> - 2017-03-06 02:12 +0000
      Re: Slightly OT: Wine fridge temperature hysteresis? Joerg <news@analogconsultants.com> - 2017-03-06 08:06 -0800
        Re: Slightly OT: Wine fridge temperature hysteresis? Mike Perkins <spam@spam.com> - 2017-03-07 00:56 +0000
          Re: Slightly OT: Wine fridge temperature hysteresis? Joerg <news@analogconsultants.com> - 2017-03-07 07:32 -0800
            Re: Slightly OT: Wine fridge temperature hysteresis? makolber@yahoo.com - 2017-03-07 10:57 -0800
              Re: Slightly OT: Wine fridge temperature hysteresis? makolber@yahoo.com - 2017-03-07 10:59 -0800
                Re: Slightly OT: Wine fridge temperature hysteresis? Joerg <news@analogconsultants.com> - 2017-03-07 11:19 -0800

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#450327 — Slightly OT: Wine fridge temperature hysteresis?

What is normal for a temperature hysteresis (or "dead band") in a wine 
fridge? I am seeing 5F and more. It is a Vinotemp VT182.

Long story short I modified it to become a beer fermenting chamber and 
added heating capability. Due to it being winter out here it is operated 
in heat mode right now and the original controller is still used to 
measure and regulate temps. I didn't hack the micro controller part of 
it (yet ...).  Currently it is set to 65F. Heat came on at 63F or 64F 
and now it's topped out at 69F, still heating. Since the heater is wimpy 
that means it may be always on until it gets warmer outside. No problem, 
just got me to wonder why the hysteresis is so large on these.

In case someone wants to know what's currently in there: American Wheat, 
Honey Porter, IPA and Pale Ale. It sure beats having all these buckets 
standing around in the downstairs room and having to run the pellet 
stove just for the fermenters.

-- 
Regards, Joerg

http://www.analogconsultants.com/

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#450349

On 6/03/2017 5:31 AM, Joerg wrote:
> What is normal for a temperature hysteresis (or "dead band") in a wine
> fridge? I am seeing 5F and more. It is a Vinotemp VT182.
>
> Long story short I modified it to become a beer fermenting chamber and
> added heating capability. Due to it being winter out here it is operated
> in heat mode right now and the original controller is still used to
> measure and regulate temps. I didn't hack the micro controller part of
> it (yet ...).  Currently it is set to 65F. Heat came on at 63F or 64F
> and now it's topped out at 69F, still heating. Since the heater is wimpy
> that means it may be always on until it gets warmer outside. No problem,
> just got me to wonder why the hysteresis is so large on these.
>
> In case someone wants to know what's currently in there: American Wheat,
> Honey Porter, IPA and Pale Ale. It sure beats having all these buckets
> standing around in the downstairs room and having to run the pellet
> stove just for the fermenters.
>
Air temp in a fridge is notoriously variable, both in temp due to 
hysteresis, as you observe, and also in location inside the chamber.

5 deg for a typical fridge is pretty good, the controllers are not all 
that smart, in general.

It is usually assumed that the liquids in the fridge hold at least the 
liquid at a relatively stable temp, due to the high heat capacity.

So put more beer in !

-- 
Regards,

Adrian Jansen

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#450353

On 2017-03-05 13:46, Adrian Jansen wrote:
> On 6/03/2017 5:31 AM, Joerg wrote:
>> What is normal for a temperature hysteresis (or "dead band") in a wine
>> fridge? I am seeing 5F and more. It is a Vinotemp VT182.
>>
>> Long story short I modified it to become a beer fermenting chamber and
>> added heating capability. Due to it being winter out here it is operated
>> in heat mode right now and the original controller is still used to
>> measure and regulate temps. I didn't hack the micro controller part of
>> it (yet ...).  Currently it is set to 65F. Heat came on at 63F or 64F
>> and now it's topped out at 69F, still heating. Since the heater is wimpy
>> that means it may be always on until it gets warmer outside. No problem,
>> just got me to wonder why the hysteresis is so large on these.
>>
>> In case someone wants to know what's currently in there: American Wheat,
>> Honey Porter, IPA and Pale Ale. It sure beats having all these buckets
>> standing around in the downstairs room and having to run the pellet
>> stove just for the fermenters.
>>
> Air temp in a fridge is notoriously variable, both in temp due to
> hysteresis, as you observe, and also in location inside the chamber.
>

It's measured at the walls, not air. That changes very slowly, takes hours.


> 5 deg for a typical fridge is pretty good, the controllers are not all
> that smart, in general.
>

Ok, but for a uC-based controller that seems a bit much. My external uC 
controller for another fridge is programmable in the hysteresis and 2F 
is max there.


> It is usually assumed that the liquids in the fridge hold at least the
> liquid at a relatively stable temp, due to the high heat capacity.
>

Not really. The two sensors at the walls take easily an hour to change 
by 1F and the large liquid bodies (5 gallons of 18 liters each) follow 
that with some lag. A 5F hysteresis makes the fermenter contents meander 
by 2-3F. That's ok but I wonder why they chose such a large hysteresis.


> So put more beer in !
>

It's already maxed out. After scrapping out a lot of stuff and building 
new shelves I was able to cram in four fermenters. So the total is 20 
gallons or 72 liters. That's a lotta beer.

Anyhow, I just switched it back to 64F because the top part was about to 
exceed 70F and that becomes borderline for some yeast strains. This 
unfortunately means it's likely going to drop to 63F before the heater 
kicks back on. Not very close to the lower borderline of 58F but this 
does slow down the fermentation unnecessarily.

Some day I may have to build a better controller.

-- 
Regards, Joerg

http://www.analogconsultants.com/

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#450374

On 6/03/2017 8:43 AM, Joerg wrote:
> On 2017-03-05 13:46, Adrian Jansen wrote:
>> On 6/03/2017 5:31 AM, Joerg wrote:
>>> What is normal for a temperature hysteresis (or "dead band") in a wine
>>> fridge? I am seeing 5F and more. It is a Vinotemp VT182.
>>>
>>> Long story short I modified it to become a beer fermenting chamber and
>>> added heating capability. Due to it being winter out here it is operated
>>> in heat mode right now and the original controller is still used to
>>> measure and regulate temps. I didn't hack the micro controller part of
>>> it (yet ...).  Currently it is set to 65F. Heat came on at 63F or 64F
>>> and now it's topped out at 69F, still heating. Since the heater is wimpy
>>> that means it may be always on until it gets warmer outside. No problem,
>>> just got me to wonder why the hysteresis is so large on these.
>>>
>>> In case someone wants to know what's currently in there: American Wheat,
>>> Honey Porter, IPA and Pale Ale. It sure beats having all these buckets
>>> standing around in the downstairs room and having to run the pellet
>>> stove just for the fermenters.
>>>
>> Air temp in a fridge is notoriously variable, both in temp due to
>> hysteresis, as you observe, and also in location inside the chamber.
>>
>
> It's measured at the walls, not air. That changes very slowly, takes hours.
>
>
>> 5 deg for a typical fridge is pretty good, the controllers are not all
>> that smart, in general.
>>
>
> Ok, but for a uC-based controller that seems a bit much. My external uC
> controller for another fridge is programmable in the hysteresis and 2F
> is max there.
>
>
>> It is usually assumed that the liquids in the fridge hold at least the
>> liquid at a relatively stable temp, due to the high heat capacity.
>>
>
> Not really. The two sensors at the walls take easily an hour to change
> by 1F and the large liquid bodies (5 gallons of 18 liters each) follow
> that with some lag. A 5F hysteresis makes the fermenter contents meander
> by 2-3F. That's ok but I wonder why they chose such a large hysteresis.
>
>
>> So put more beer in !
>>
>
> It's already maxed out. After scrapping out a lot of stuff and building
> new shelves I was able to cram in four fermenters. So the total is 20
> gallons or 72 liters. That's a lotta beer.
>
> Anyhow, I just switched it back to 64F because the top part was about to
> exceed 70F and that becomes borderline for some yeast strains. This
> unfortunately means it's likely going to drop to 63F before the heater
> kicks back on. Not very close to the lower borderline of 58F but this
> does slow down the fermentation unnecessarily.
>
> Some day I may have to build a better controller.
>
Yup, throw out the existing controller and put in something that does 
proper PID.

-- 
Regards,

Adrian Jansen

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#450452

On 2017-03-05 17:23, Adrian Jansen wrote:
> On 6/03/2017 8:43 AM, Joerg wrote:
>> On 2017-03-05 13:46, Adrian Jansen wrote:
>>> On 6/03/2017 5:31 AM, Joerg wrote:
>>>> What is normal for a temperature hysteresis (or "dead band") in a wine
>>>> fridge? I am seeing 5F and more. It is a Vinotemp VT182.
>>>>
>>>> Long story short I modified it to become a beer fermenting chamber and
>>>> added heating capability. Due to it being winter out here it is
>>>> operated
>>>> in heat mode right now and the original controller is still used to
>>>> measure and regulate temps. I didn't hack the micro controller part of
>>>> it (yet ...).  Currently it is set to 65F. Heat came on at 63F or 64F
>>>> and now it's topped out at 69F, still heating. Since the heater is
>>>> wimpy
>>>> that means it may be always on until it gets warmer outside. No
>>>> problem,
>>>> just got me to wonder why the hysteresis is so large on these.
>>>>
>>>> In case someone wants to know what's currently in there: American
>>>> Wheat,
>>>> Honey Porter, IPA and Pale Ale. It sure beats having all these buckets
>>>> standing around in the downstairs room and having to run the pellet
>>>> stove just for the fermenters.
>>>>
>>> Air temp in a fridge is notoriously variable, both in temp due to
>>> hysteresis, as you observe, and also in location inside the chamber.
>>>
>>
>> It's measured at the walls, not air. That changes very slowly, takes
>> hours.
>>
>>
>>> 5 deg for a typical fridge is pretty good, the controllers are not all
>>> that smart, in general.
>>>
>>
>> Ok, but for a uC-based controller that seems a bit much. My external uC
>> controller for another fridge is programmable in the hysteresis and 2F
>> is max there.
>>
>>
>>> It is usually assumed that the liquids in the fridge hold at least the
>>> liquid at a relatively stable temp, due to the high heat capacity.
>>>
>>
>> Not really. The two sensors at the walls take easily an hour to change
>> by 1F and the large liquid bodies (5 gallons of 18 liters each) follow
>> that with some lag. A 5F hysteresis makes the fermenter contents meander
>> by 2-3F. That's ok but I wonder why they chose such a large hysteresis.
>>
>>
>>> So put more beer in !
>>>
>>
>> It's already maxed out. After scrapping out a lot of stuff and building
>> new shelves I was able to cram in four fermenters. So the total is 20
>> gallons or 72 liters. That's a lotta beer.
>>
>> Anyhow, I just switched it back to 64F because the top part was about to
>> exceed 70F and that becomes borderline for some yeast strains. This
>> unfortunately means it's likely going to drop to 63F before the heater
>> kicks back on. Not very close to the lower borderline of 58F but this
>> does slow down the fermentation unnecessarily.
>>
>> Some day I may have to build a better controller.
>>
> Yup, throw out the existing controller and put in something that does
> proper PID.
>

Doesn't need PID, just a smaller hysteresis will do fine. That's what I 
did with another fridge before, using an external controller. Worked 
nicely all summer last year. However, that fridge can only hold one 
fermenter. I might still use that on occasion if I want to brew a 
Pilsener or Bock which requires lagering for weeks at very low temperatures.

-- 
Regards, Joerg

http://www.analogconsultants.com/

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#450494

In article <ei3ik9Fs8otU1@mid.individual.net>,
Joerg  <news@analogconsultants.com> wrote:

>Not really. The two sensors at the walls take easily an hour to change 
>by 1F and the large liquid bodies (5 gallons of 18 liters each) follow 
>that with some lag. A 5F hysteresis makes the fermenter contents meander 
>by 2-3F. That's ok but I wonder why they chose such a large hysteresis.

What's the typical cycle-on-and-off period, in your installation, with
the existing 5-degree hysteresis?

I suspect that trying for a tighter hysteresis might have required the
compressor to cycle on and off rather frequently.  This can be
destructive - refrigerator and airco systems need some "idle time"
after shutting off, for the pressure in the loop to equalize.  The
compressor usually has a timer on it, to prevent attempts at a rapid
restart.

Keeping the hysteresis tighter, while still maintaining a safe cycle
period for the compressor, might have required better insulation
(which is bulky and/or costly).

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#450499

On 2017-03-06 11:41, Dave Platt wrote:
> In article <ei3ik9Fs8otU1@mid.individual.net>,
> Joerg  <news@analogconsultants.com> wrote:
>
>> Not really. The two sensors at the walls take easily an hour to change
>> by 1F and the large liquid bodies (5 gallons of 18 liters each) follow
>> that with some lag. A 5F hysteresis makes the fermenter contents meander
>> by 2-3F. That's ok but I wonder why they chose such a large hysteresis.
>
> What's the typical cycle-on-and-off period, in your installation, with
> the existing 5-degree hysteresis?
>

Can't say for cooling because it is too cold right now. So heat only. 
With the 21W heater that I made each cycle is more than 20 hours. In 
part because it has a hard time to crank out the last degree.


> I suspect that trying for a tighter hysteresis might have required the
> compressor to cycle on and off rather frequently.  This can be
> destructive - refrigerator and airco systems need some "idle time"
> after shutting off, for the pressure in the loop to equalize.  The
> compressor usually has a timer on it, to prevent attempts at a rapid
> restart.
>
> Keeping the hysteresis tighter, while still maintaining a safe cycle
> period for the compressor, might have required better insulation
> (which is bulky and/or costly).
>

When I test ran it in the garage, setting it to 45F, the cycle times 
were hours so that doesn't seem to be the problem. Right now I can't 
test cooling anymore because I've got four beer fermenters in it and if 
I'd cool the fermentation would stall.

Considering that it has a >13A compressor all this seems overkill.

-- 
Regards, Joerg

http://www.analogconsultants.com/

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#450355

Den søndag den 5. marts 2017 kl. 20.31.48 UTC+1 skrev Joerg:
> What is normal for a temperature hysteresis (or "dead band") in a wine 
> fridge? I am seeing 5F and more. It is a Vinotemp VT182.
> 
> Long story short I modified it to become a beer fermenting chamber and 
> added heating capability. Due to it being winter out here it is operated 
> in heat mode right now and the original controller is still used to 
> measure and regulate temps. I didn't hack the micro controller part of 
> it (yet ...).  Currently it is set to 65F. Heat came on at 63F or 64F 
> and now it's topped out at 69F, still heating. Since the heater is wimpy 
> that means it may be always on until it gets warmer outside. No problem, 
> just got me to wonder why the hysteresis is so large on these.
> 
> In case someone wants to know what's currently in there: American Wheat, 
> Honey Porter, IPA and Pale Ale. It sure beats having all these buckets 
> standing around in the downstairs room and having to run the pellet 
> stove just for the fermenters.
> 

maybe it is just that you don't want the compressor (or heating relay) to 
cycle on and off all the time

heating with a solidstate switch you could make the hysteresis ~0

-Lasse

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#450357

On 2017-03-05 14:52, Lasse Langwadt Christensen wrote:
> Den søndag den 5. marts 2017 kl. 20.31.48 UTC+1 skrev Joerg:
>> What is normal for a temperature hysteresis (or "dead band") in a wine
>> fridge? I am seeing 5F and more. It is a Vinotemp VT182.
>>
>> Long story short I modified it to become a beer fermenting chamber and
>> added heating capability. Due to it being winter out here it is operated
>> in heat mode right now and the original controller is still used to
>> measure and regulate temps. I didn't hack the micro controller part of
>> it (yet ...).  Currently it is set to 65F. Heat came on at 63F or 64F
>> and now it's topped out at 69F, still heating. Since the heater is wimpy
>> that means it may be always on until it gets warmer outside. No problem,
>> just got me to wonder why the hysteresis is so large on these.
>>
>> In case someone wants to know what's currently in there: American Wheat,
>> Honey Porter, IPA and Pale Ale. It sure beats having all these buckets
>> standing around in the downstairs room and having to run the pellet
>> stove just for the fermenters.
>>
>
> maybe it is just that you don't want the compressor (or heating relay) to
> cycle on and off all the time
>

That can be maintained otherwise and actually is. They programmed a 
delay into it so if someone changes the temperatures back and forth very 
fast on the control panel it waits a long time to turn on the 
compressor. This avoids short-cycling.


> heating with a solidstate switch you could make the hysteresis ~0
>

Unfortunately I can't. It is a Samsung uC with hard to decipher P/N, 
could be 1708B. Next to impossible to change the code in there.

-- 
Regards, Joerg

http://www.analogconsultants.com/

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#450363

Den mandag den 6. marts 2017 kl. 00.43.37 UTC+1 skrev Joerg:
> On 2017-03-05 14:52, Lasse Langwadt Christensen wrote:
> > Den søndag den 5. marts 2017 kl. 20.31.48 UTC+1 skrev Joerg:
> >> What is normal for a temperature hysteresis (or "dead band") in a wine
> >> fridge? I am seeing 5F and more. It is a Vinotemp VT182.
> >>
> >> Long story short I modified it to become a beer fermenting chamber and
> >> added heating capability. Due to it being winter out here it is operated
> >> in heat mode right now and the original controller is still used to
> >> measure and regulate temps. I didn't hack the micro controller part of
> >> it (yet ...).  Currently it is set to 65F. Heat came on at 63F or 64F
> >> and now it's topped out at 69F, still heating. Since the heater is wimpy
> >> that means it may be always on until it gets warmer outside. No problem,
> >> just got me to wonder why the hysteresis is so large on these.
> >>
> >> In case someone wants to know what's currently in there: American Wheat,
> >> Honey Porter, IPA and Pale Ale. It sure beats having all these buckets
> >> standing around in the downstairs room and having to run the pellet
> >> stove just for the fermenters.
> >>
> >
> > maybe it is just that you don't want the compressor (or heating relay) to
> > cycle on and off all the time
> >
> 
> That can be maintained otherwise and actually is. They programmed a 
> delay into it so if someone changes the temperatures back and forth very 
> fast on the control panel it waits a long time to turn on the 
> compressor. This avoids short-cycling.
> 

sure but there is a limit to how tight you can make it if you also want a 
say +10 minute wait period between starts to limit wear on the compressor

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#450453

On 2017-03-05 16:15, Lasse Langwadt Christensen wrote:
> Den mandag den 6. marts 2017 kl. 00.43.37 UTC+1 skrev Joerg:
>> On 2017-03-05 14:52, Lasse Langwadt Christensen wrote:
>>> Den søndag den 5. marts 2017 kl. 20.31.48 UTC+1 skrev Joerg:
>>>> What is normal for a temperature hysteresis (or "dead band") in a wine
>>>> fridge? I am seeing 5F and more. It is a Vinotemp VT182.
>>>>
>>>> Long story short I modified it to become a beer fermenting chamber and
>>>> added heating capability. Due to it being winter out here it is operated
>>>> in heat mode right now and the original controller is still used to
>>>> measure and regulate temps. I didn't hack the micro controller part of
>>>> it (yet ...).  Currently it is set to 65F. Heat came on at 63F or 64F
>>>> and now it's topped out at 69F, still heating. Since the heater is wimpy
>>>> that means it may be always on until it gets warmer outside. No problem,
>>>> just got me to wonder why the hysteresis is so large on these.
>>>>
>>>> In case someone wants to know what's currently in there: American Wheat,
>>>> Honey Porter, IPA and Pale Ale. It sure beats having all these buckets
>>>> standing around in the downstairs room and having to run the pellet
>>>> stove just for the fermenters.
>>>>
>>>
>>> maybe it is just that you don't want the compressor (or heating relay) to
>>> cycle on and off all the time
>>>
>>
>> That can be maintained otherwise and actually is. They programmed a
>> delay into it so if someone changes the temperatures back and forth very
>> fast on the control panel it waits a long time to turn on the
>> compressor. This avoids short-cycling.
>>
>
> sure but there is a limit to how tight you can make it if you also want a
> say +10 minute wait period between starts to limit wear on the compressor
>

The simple on-off controller on the old fridge ran on a 2F hysteresis 
just fine. Even less than 1F worked but I kept it set at 2F. Insulation 
and thus time lag on both fridges is similar.

-- 
Regards, Joerg

http://www.analogconsultants.com/

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#450372

On Sunday, March 5, 2017 at 6:43:37 PM UTC-5, Joerg wrote:

> Unfortunately I can't. It is a Samsung uC with hard to decipher P/N, 
> could be 1708B. Next to impossible to change the code in there.
> 
> -- 
> Regards, Joerg
>

Do  a search on aliexpress and Ebay for  W1209.  It is a cheap temp controler.  Will work for either heating or cooling, but not both at the same time.

                                       Dan

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#450433

On 3/5/2017 7:10 PM, dcaster@krl.org wrote:
> On Sunday, March 5, 2017 at 6:43:37 PM UTC-5, Joerg wrote:
>
>> Unfortunately I can't. It is a Samsung uC with hard to decipher P/N,
>> could be 1708B. Next to impossible to change the code in there.
>>
>> --
>> Regards, Joerg
>>
>
> Do  a search on aliexpress and Ebay for  W1209.  It is a cheap temp controler.  Will work for either heating or cooling, but not both at the same time.
>
>                                        Dan
>

  Several years ago I bought a STC-1000 after reading about how 
homebrewers were using it with success.
> https://www.google.com/search?q=stc-1000&ie=utf-8&oe=utf-8

I have it wired up in a box with a duplex outlet with separately
wired sockets, one for heating one for cooling.

                                 Mikek

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

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#450445

You could mount a small heater next to the sensor and trick it into having less hysteresis..

no change to the code needed


Google "anticipator"


mark

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#450456

On 2017-03-06 04:14, amdx wrote:
> On 3/5/2017 7:10 PM, dcaster@krl.org wrote:
>> On Sunday, March 5, 2017 at 6:43:37 PM UTC-5, Joerg wrote:
>>
>>> Unfortunately I can't. It is a Samsung uC with hard to decipher P/N,
>>> could be 1708B. Next to impossible to change the code in there.
>>>
>>> --
>>> Regards, Joerg
>>>
>>
>> Do  a search on aliexpress and Ebay for  W1209.  It is a cheap temp
>> controler.  Will work for either heating or cooling, but not both at
>> the same time.
>>
>>                                        Dan
>>

I already have a Willhi controller from China, works great. However, it 
needs mains power and I wanted to make things more neat and integrated 
in this larger wine fridge. Inside there's only 5V at a few tens of mA 
available.

>
>   Several years ago I bought a STC-1000 after reading about how
> homebrewers were using it with success.
>> https://www.google.com/search?q=stc-1000&ie=utf-8&oe=utf-8
>
> I have it wired up in a box with a duplex outlet with separately
> wired sockets, one for heating one for cooling.
>

Check out the Inkbird controllers. They come with cool/heat 
simultaneously. I found this not to be necessary though because we don't 
have wild climate swings out here.

-- 
Regards, Joerg

http://www.analogconsultants.com/

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#450366

>"maybe it is just that you don't want the compressor (or heating relay) to
cycle on and off all the time "

You beat me to it. For cooling the compressor has to build up pressure. For heating, if it is electric, the heating element(s) are very inefficient when first turned on. 

As far as the heating goes, which is probably the issue this time of year in the northern hemisphere, throttling might work better. That way the elements never get completely cold and thus require more current to get back up and running. 

This is practically impossible for the cooling end of the kit though, although I did notice something in a Dadge van that seriously impressed me. After sitting in  the hot sun the AC was COLD ! I mean cold.

I am not an engineer, I just play one on TV, but this got my mind working. To have instant AC in a car what they must do is to close the valve to maintain the pressure of the Freon. 

In fact the AC you get today is junk. Cars used to have a thermostatically controlled expansion valve, now they use a cheap cap tube. They also used to have an accumulator which regulated the overall pressure in the system during the wide changes in operating conditions. It also had the side effect of having the thing still work when some of the Freon leaked out. Now the system simply shuts down when the low side gets to a certain point. 

Building a cabinet for in house use is a far easier engineering task. Think of a car n the middle of summer with a 455 cubic inch engine in it. Underhood temperatures get so high that it might burn the oil. And you have to dissipate heat into that to put out like 50 degree air into the cab. This device has no such difficulties. First of all, it is usually in a house or other area where it as already climate controlled. 

But some hysteresis is necessary for efficiency. Do you want to start a compressor or heating element every five seconds ? In the past, physical limitations caused this, but now with electronic sensors and whatnot it can become necessary to design it into the system. Depends on what you're building, and this sounds like it. 

Referring to electronic, (umm that is what this is BTW) it is like a feedback loop.. Much concern has been given to this. When you design a servo type system, which includes everything from power supplies to FM tuners, the gain and speed of the feedback network has to be controlled so that the system does not oscillate. Too much gain and the whole thing might go up in smoke. 

Electronics is a part of physics. Remember window AC units used to have those copper things that sensed the temperature of the air incoming to the evaporator ? Well they don't need those anymore. 

It is all the same thing, all sciences. One exception might be nuclear, but I have very little interest in that. I also think (I know someone is going to hook on this) that Einstein purposely sabotaged his own work when releasing his new theory. He made the formulae that they use to try to claim that it is a different tie in different parts of the universe. Don't forget that he only agreed to help develop the bomb because he was convinced that if we didn't, the Nazis would have. 

In his position I would have probably done the same. If time travel is indeed possible, which I firmly doubt, mankind cannot be enabled to do it. Can you imagine the abuse possible ? 

Last but not least, look up the etymology off the word hysteresis and then look up what a hysterectomy is.

The whole meaning might come to you, or it might not.

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#450369

Den mandag den 6. marts 2017 kl. 01.27.00 UTC+1 skrev jurb...@gmail.com:
> >"maybe it is just that you don't want the compressor (or heating relay) to
> cycle on and off all the time "
> 
> You beat me to it. For cooling the compressor has to build up pressure. For heating, if it is electric, the heating element(s) are very inefficient when first turned on. 
> 
> As far as the heating goes, which is probably the issue this time of year in the northern hemisphere, throttling might work better. That way the elements never get completely cold and thus require more current to get back up and running. 
> 
> This is practically impossible for the cooling end of the kit though, although I did notice something in a Dadge van that seriously impressed me. After sitting in  the hot sun the AC was COLD ! I mean cold.
> 
> I am not an engineer, I just play one on TV, but this got my mind working. To have instant AC in a car what they must do is to close the valve to maintain the pressure of the Freon. 
> 

I don't have any experience with automotive ACs but, with a regular electric 
compresor it quickly gets complicated, you can't just close a valve then 
the input side gets into vacuum which you want to avoid so you don't suck in 
air if there is any leaks and you also miss compressor cooling and lubrication because that is with the refrigerant

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#450409

>"I don't have any experience with automotive ACs but, with a regular electric
compresor it quickly gets complicated, you can't just close a valve then
the input side gets into vacuum which you want to avoid so you don't suck in
air if there is any leaks and you also miss compressor cooling and lubrication because that is with the refrigerant "

Oh boy. You opened s huge cam of beans here. 

Cooling is a huge issue, you have no idea what it involves. Most people do not understand that to remove heat from you house requires us to boil stuff and then to recondnense it. You want to take a crack at that it ? 

Engineers make money because they are worth it. 

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#450371

On Sun, 05 Mar 2017 11:31:41 -0800, Joerg <news@analogconsultants.com>
wrote:

>What is normal for a temperature hysteresis (or "dead band") in a wine 
>fridge? I am seeing 5F and more. It is a Vinotemp VT182.

Our KitchenAid wine refrigerator has ~4°F hysteresis... very annoying
for an engineer to watch >:-}  But doesn't seem to hurt the wine at
all.

>
>Long story short I modified it to become a beer fermenting chamber and 
>added heating capability. Due to it being winter out here it is operated 
>in heat mode right now and the original controller is still used to 
>measure and regulate temps. I didn't hack the micro controller part of 
>it (yet ...).  Currently it is set to 65F. Heat came on at 63F or 64F 
>and now it's topped out at 69F, still heating. Since the heater is wimpy 
>that means it may be always on until it gets warmer outside. No problem, 
>just got me to wonder why the hysteresis is so large on these.
>
>In case someone wants to know what's currently in there: American Wheat, 
>Honey Porter, IPA and Pale Ale. It sure beats having all these buckets 
>standing around in the downstairs room and having to run the pellet 
>stove just for the fermenters.
		
                                        ...Jim Thompson
-- 
| James E.Thompson                                 |    mens     |
| Analog Innovations                               |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| STV, Queen Creek, AZ 85142    Skype: skypeanalog |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |

     Thinking outside the box... producing elegant solutions.

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#450459

On 2017-03-05 16:53, Jim Thompson wrote:
> On Sun, 05 Mar 2017 11:31:41 -0800, Joerg <news@analogconsultants.com>
> wrote:
>
>> What is normal for a temperature hysteresis (or "dead band") in a wine
>> fridge? I am seeing 5F and more. It is a Vinotemp VT182.
>
> Our KitchenAid wine refrigerator has ~4°F hysteresis... very annoying
> for an engineer to watch >:-}  But doesn't seem to hurt the wine at
> all.
>

Ah, so then 5F would be almost normal in the market. I wonder why they 
do that.

I'll see what the fermentation process says to that. If not happy I'll 
build my own controller. It's already on the schematic, just a lot of 
soldering. This would also allow me to strap a LM35-based sensor pod 
directly to a fermenter.

[...]

-- 
Regards, Joerg

http://www.analogconsultants.com/

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