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Old 01-07-2014, 07:14 AM   #11
tob77
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I wonder if you could post some more info on your sparker setup and how you are using it - manually, through code, etc..
The spark module can either be energized automatically or by a manual push button on my control panel. It gets energized for about 3 seconds every time the program turns the burner on. The burner is turned on and off several times throughout the brew program. For example, I programmed it to turn off during dough in, grain bag removal, and a high temp shut off. The burner will then automatically relight by pressing the next step button (dough in, and bag removal) or when the temperature drops to an acceptable level. The spark module is another leftover from my original configuration that I built back in 2002. I might use a pilot light if I was starting over again to avoid the EMI, but then again a pilot might blow out in gusty wind so...

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I'd also really like to see the inside of your control box.
No you don't, it's a disaster. I fabricated the control panel back when I had access to my schools metal shop, and I didn't build it with accessibility in mind. As a result, it is very cramped and extremely difficult to install and wire components. All of the components are securely mounted, but there is an ugly tangle of wires connecting everything.

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Finally, I don't see a pump on your recirculation arm, so I'm curious as to how you are siphoning the wort from bottom to top.
Get your magnifying glass out I'm using one of the cheap tan 12vdc pumps from ebay:http://www.homebrewtalk.com/f11/chea...t-pump-375904/ It works good enough as long as you don't get any turb stuck in it. I'm sure a bigger pump would be a lot more reliable and be better at mixing the mash. I'll probably get a better pump if/when this $22 pump gives out.

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I see you're in the North Bay, do you ever come south? I'd love to hang out and talk beer/kit. I'm going to try hanging out at the Silicon Valley Sudzers meetup this Friday in Los Altos
Sadly, I don't get out much. Between work and family I don't have much spare time these days (except after the kids go to bed which is when I did all my programming). My kids are finally getting old enough to not need constant attention, but...I've now got another one coming in a couple of months I fear the new born will put a damper on my brewing for a few months.
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Old 01-07-2014, 03:44 PM   #12
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The only problem with spark modules is that they produce a lot of electromagnetic interference. I have spent quite a bit of time trying to shield my system from the problems it introduces. Try to keep the spark gap as small as possible. I have found that less EMI is produced with smaller spark gaps. I have also found that for whatever reason that some of the electric outlets in my house are grounded better than others. I can not brew off of one of the outlets in my garage because of the poor grounding and resultant EMI from the spark module. As it is, I still get some problems with my LCD on my control panel from time to time when the spark module fires. To counter this I have programmed an initialization command to the LCD after the spark module has been automatically fired. For what it's worth, the rpi has never been reset due to EMI. The only problems I have seen were in the 1-wire comms and the LCD display.

Thanks for pointing out the MAX31850, I haven't seen that before. I'll probably look into this sometime in the future. I'd have to figure out somewhere to place the thermocouple that wouldn't burn up. Usually the thermocouples are placed on pilot lights. I could probably get away with putting one close to the flame but not in the flame but idk. Do you have any thoughts on this?
Hmm, I hadn't thought of EMI, but those sparker circuits are likely several kV, so I guess that could indeed be a problem. I guess a solution would be to go with a hot surface ignitor. I plan to build mine completely headless, so I wonder if it would be a problem? As for flame sensing, there are really two simple methods, thermocouple and flame rectification. For the former, it should be relatively simple to connect an off-the-shelf furnace thermocouple from McMaster-Carr to the MAX31850 (or MAX31851). The thermocouple produces a small voltage when hot, which is then amplified and converted to a digital 1-wire signal by the MAX31851. Precision is not important, as it should be easy to distinguish flame or no flame irrespective of the furnace thermocouple used. More recent furnaces, dryers, etc use electronic flame sensors that use something called flame rectification. Basically, an AC signal is sent through the flame sensor, and if flame exists, the sensor acts as a diode. It would be fairly straightforward to develop a circuit to detect rectification of an AC signal, and thus the presence of flame. Both approaches are viable, but the thermocouple method would likely be cheaper and easier to implement.
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Old 01-07-2014, 05:47 PM   #13
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Sadly, I don't get out much. Between work and family I don't have much spare time these days (except after the kids go to bed which is when I did all my programming). My kids are finally getting old enough to not need constant attention, but...I've now got another one coming in a couple of months I fear the new born will put a damper on my brewing for a few months.
Hence the need for automation

I'm in much the same boat, myself, but now that the baby is in full-on toddlerhood, I'm regaining some semblance of personhood

Good luck with the new one on the way! Your project really is looking great, and I'm hoping your inspiration will push me to take mine to the next level
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Old 01-07-2014, 09:00 PM   #14
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To eliminate the interference from the spark module you should try running a simple ground wire to the frame or burner. A simple wire to a steel tent stake you can insert into the ground should do the trick and keep it mobile

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Old 01-08-2014, 03:02 AM   #15
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Why not just use a burner pilot instead of the igniter. Lets say a valve to the pilot that you open and light at the beginning of the brew. I think that would simplify your issue. This is how I would handle it..also you would get a faster ignition of the flame. Just make sure to shield it from the wind if its used out side.

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Old 01-08-2014, 04:30 AM   #16
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To eliminate the interference from the spark module you should try running a simple ground wire to the frame or burner. A simple wire to a steel tent stake you can insert into the ground should do the trick and keep it mobile
On my burner, I run one of the ignitor controller terminals to the frame of the burner. Would running this to an actual ground electrode eliminate EMI? What about just using equipment ground from a control panel?
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Old 01-08-2014, 04:34 AM   #17
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Why not just use a burner pilot instead of the igniter. Lets say a valve to the pilot that you open and light at the beginning of the brew. I think that would simplify your issue. This is how I would handle it..also you would get a faster ignition of the flame. Just make sure to shield it from the wind if its used out side.
I think the issue is wind, and I'm not sure it would be possible to shield the pilot enough without preventing exhaust fumes from exiting the burner properly. You might be able to eliminate most problems, but the potential loss of the pilot flame due to a gust of wind could make things go boom. This is really only an issue if you truly want the burner to be hands off. But part of the reason for automating a burner would be to avoid having to babysit it during the mash.
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Old 01-08-2014, 05:56 AM   #18
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I guess a solution would be to go with a hot surface ignitor. I plan to build mine completely headless, so I wonder if it would be a problem?
I like this idea, I might go the hot surface ignitor if I was to do it again. The EMI mostly causes issues with low current signal lines. Like I said before, I have only seen issues on my LCD and 1-wire bus. The 1-wire bus is no longer an issue since I narrowed the spark gap, and stopped using the one badly grounded outlet in my garage. Additionally, I added some code to filter out any bad readings from the DS18B20. The DS18B20 will return a reading of 185 deg F if it is reset. I filter this out by looking at the previous value to determine if it has instantaneously jumped to 185 degrees. The LCD completely goes crazy when it gets hit with the EMI. However, a quick init command quickly fixes the problem. There are a few other places that you could potentially see issues even with a headless setup. All of the gpio are low current lines so they could potentially be affected. Keeping all of the wires associated with the gpio as short as possible should minimize any potential problems.

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As for flame sensing, there are really two simple methods, thermocouple and flame rectification. For the former, it should be relatively simple to connect an off-the-shelf furnace thermocouple from McMaster-Carr to the MAX31850 (or MAX31851). The thermocouple produces a small voltage when hot, which is then amplified and converted to a digital 1-wire signal by the MAX31851. Precision is not important, as it should be easy to distinguish flame or no flame irrespective of the furnace thermocouple used. More recent furnaces, dryers, etc use electronic flame sensors that use something called flame rectification. Basically, an AC signal is sent through the flame sensor, and if flame exists, the sensor acts as a diode. It would be fairly straightforward to develop a circuit to detect rectification of an AC signal, and thus the presence of flame. Both approaches are viable, but the thermocouple method would likely be cheaper and easier to implement.
Where would you put the thermocouple? Do you think that they could withstand the prolonged exposure to the burner? I am not familiar with flame rectification. This might be an interesting option if it can withstand the high temps from the burner. Are these used in pilotless applications?

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To eliminate the interference from the spark module you should try running a simple ground wire to the frame or burner. A simple wire to a steel tent stake you can insert into the ground should do the trick and keep it mobile
Not a bad idea, I might have to try the stake idea sometime. all of my equipment is grounded to the house ground right now but a more direct route to the earth might work a little better.

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Why not just use a burner pilot instead of the igniter. Lets say a valve to the pilot that you open and light at the beginning of the brew. I think that would simplify your issue. This is how I would handle it..also you would get a faster ignition of the flame. Just make sure to shield it from the wind if its used out side.
I like the simplicity of the pilot but I'd be worried about the wind blowing it out. I would absolutely not use a pilot unless a thermocouple was used with it. I think I've seen a few threads where people use some Honeywell pilot valves off the shelf. Some of these might even have electric ignition for the pilot.
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Old 01-08-2014, 04:04 PM   #19
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You could use a thermopile - which is a device that generates electric current when exposed to heat. http://www.amazon.com/Thermopile-Mil.../dp/B005DUUKY8

In fact, my brinkmann turkey burner came with one as part of the "safety" equipment.

Many pilot light systems for gas fireplaces and furnaces combine a thermopile, pilot, and spark ignitor, e.g. http://www.amazon.com/Reliance-State...rds=thermopile

They are designed to be exposed to high heat for long periods of time.

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In bottles: Last Day IPA, AAPL American Pale Ale
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The answer to the ultimate question of life, the universe, and everything? 42. The number of bottles in my first batch of homebrew? 42. Coincidence? I think not.

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Old 01-08-2014, 05:37 PM   #20
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In fact, my brinkmann turkey burner came with one as part of the "safety" equipment. ..They are designed to be exposed to high heat for long periods of time.
Where is the thermopile mounted on your brinkmann? Is it directly in the flame?
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