Ss Brewing Technologies Giveaway!

Home Brew Forums > Home Brewing Beer > Electric Brewing > PWM..Show us How
Reply
 
LinkBack Thread Tools
Old 03-30-2012, 03:56 PM   #281
yjfun
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jun 2010
Location: Arlington, Washington
Posts: 225
Liked 2 Times on 2 Posts

Default

I'm running the bakatronics kit with the 2.2 cap and the only thing I noticed is my element range seems to be from about 10%on to 90% on. I can't shut it all the way down or get full power from it.

__________________
yjfun is offline
 
Reply With Quote Quick reply to this message
Old 03-30-2012, 05:12 PM   #282
GregKelley
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2006
Location: North Royalton, OH
Posts: 128
Liked 1 Times on 1 Posts

Default

Quote:
Originally Posted by yjfun View Post
I'm running the bakatronics kit with the 2.2 cap and the only thing I noticed is my element range seems to be from about 10%on to 90% on. I can't shut it all the way down or get full power from it.
Hmm. I'm wondering if I should then add a simple switch to my PWM layout so that I can bypass the circuit and just feed the 5v and ground directly to the SSR. Throw the switch one way and the PWM is bypassed. Throw it another and the PWM is in use.
__________________
GregKelley is offline
 
Reply With Quote Quick reply to this message
Old 04-27-2012, 12:21 PM   #283
pvtschultz
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2010
Location: West Allis (Milwaukee), WI, Wisconsin
Posts: 444
Liked 6 Times on 6 Posts
Likes Given: 13

Default

If you have enough room, I would install a 240 VAC 2-pole 30A contactor to disconnect the element. The contactor costs ~$5 and then you can use a simple 10 Amp or so SPST switch to disconnect it. You are right though, without a physical disconnect, there will always be voltage at the element since the SSR is a current limiting device.

Contactor

LEDs are very simple little gizmos that just need to have the voltage going to them limited. Your application sounds quite straight forward. I would place one parallel to the supply side of your PWM circuit and one parallel to the V-out going to the SSR. The link below will help you select a resistor to place in series with the LED to keep it from burning out from over-voltage. 20 mA is a typical forward current value for LEDs so just plug in your supply voltage and then pick a color and they calculator will spit out the resistor that needs to be put in series with the LED.

http://www.hobby-hour.com/electronics/ledcalc.php

__________________
Brewing: BM's Centennial Blonde
Drinking: Brown Ale, Cherry Smoked Robust Porter (way too much smoke!)
On Deck: Dunkel, CAP, Berliner Weiss, Bock, Sour Raspberry Brown, APA...
2014 Gallons Brewed: 19
Gallons Brewed '11-'13: 250


http://www.homebrewtalk.com/f170/pvtschultzs-ebiab-build-finally-298407/
pvtschultz is offline
 
Reply With Quote Quick reply to this message
Old 04-27-2012, 01:42 PM   #284
clearwaterbrewer
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2010
Location: Clearwater, FL
Posts: 263
Liked 9 Times on 9 Posts
Likes Given: 31

Default

I would use a potentiometer with an inclusive on-off switch (separate internal switch and external contacts) to turn the 12V to the PWM circuit on and off, I would use one LED to show this on and off, and the other LED tied to the output of your PWM circuit that drives the SSR.

__________________
clearwaterbrewer is offline
 
Reply With Quote Quick reply to this message
Old 04-27-2012, 01:46 PM   #285
pvtschultz
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2010
Location: West Allis (Milwaukee), WI, Wisconsin
Posts: 444
Liked 6 Times on 6 Posts
Likes Given: 13

Default

I generally leave my potentiometer set to a experimentally determined 15% boil off rate, but a simple mark to remember the set point would be easy enough. I use a keyed switch (mostly for looks) to turn the main power on and off which feeds to my PID and PWM.

__________________
Brewing: BM's Centennial Blonde
Drinking: Brown Ale, Cherry Smoked Robust Porter (way too much smoke!)
On Deck: Dunkel, CAP, Berliner Weiss, Bock, Sour Raspberry Brown, APA...
2014 Gallons Brewed: 19
Gallons Brewed '11-'13: 250


http://www.homebrewtalk.com/f170/pvtschultzs-ebiab-build-finally-298407/
pvtschultz is offline
 
Reply With Quote Quick reply to this message
Old 05-04-2012, 02:19 AM   #286
Walker
I use secondaries. :p
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Walker's Avatar
Recipes 
 
Join Date: Sep 2005
Location: Cary, NC
Posts: 11,236
Liked 86 Times on 77 Posts
Likes Given: 11

Default

Back in post #173 I had a pic of a partially assembled breadboard with a PWM circuit on it. More than one person has copied that circuit to the letter and had issues with it working, and I realized that there is a critical error in the picture. I added a large red comment to that post to clear things up, because it will absolutely screw up the circiut behavior.

__________________
Ground Fault Brewing Co.
Walker is offline
 
Reply With Quote Quick reply to this message
Old 05-04-2012, 02:47 AM   #287
GregKelley
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2006
Location: North Royalton, OH
Posts: 128
Liked 1 Times on 1 Posts

Default

Thanks for the update, Walker. So back to the drawing you have under your red comment. You are talking about the 33μF cap, right? The negative side should connect to the negative side of the power source and the other side should be connected to pin 6 on the 555 timer? I guess I have mine turned around as well. I have a blue cap with a black stripe. I'm assuming that stripe is the negative side? The circuit seemed to work a little weird in testing but I chalked that up to the LED on the SSR not properly showing how the circuit was working.

__________________
GregKelley is offline
 
Reply With Quote Quick reply to this message
Old 05-04-2012, 02:51 AM   #288
Durhamite
Vendor, woodworker, BREWER!!!
HBT_SPONSOR.png
Vendor Ads 
Feedback Score: 0 reviews
 
Durhamite's Avatar
Recipes 
 
Join Date: Feb 2011
Location: Durham, NC
Posts: 193
Liked 16 Times on 13 Posts
Likes Given: 20

Default

Thanks again for the help Walker. Once I flipped that capacitor around it worked perfectly!


For anyone else that may be experiencing issues, mine was only turning the SSR on when I turned the potentiometer up to about 90%. Anything less than that was "off".

__________________
Durhamite is offline
 
Reply With Quote Quick reply to this message
Old 05-04-2012, 03:12 AM   #289
Walker
I use secondaries. :p
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Walker's Avatar
Recipes 
 
Join Date: Sep 2005
Location: Cary, NC
Posts: 11,236
Liked 86 Times on 77 Posts
Likes Given: 11

Default

Quote:
Originally Posted by GregKelley
Thanks for the update, Walker. So back to the drawing you have under your red comment. You are talking about the 33μF cap, right? The negative side should connect to the negative side of the power source and the other side should be connected to pin 6 on the 555 timer? I guess I have mine turned around as well. I have a blue cap with a black stripe. I'm assuming that stripe is the negative side? The circuit seemed to work a little weird in testing but I chalked that up to the LED on the SSR not properly showing how the circuit was working.

Yup. The grey stripe should be to the negative voltage node of the circuit and the non-Grey side connected to the chip. You have it backwards.

Flip it around and it should work perfectly.
__________________
Ground Fault Brewing Co.
Walker is offline
 
Reply With Quote Quick reply to this message
Old 05-07-2012, 01:05 PM   #290
GregKelley
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2006
Location: North Royalton, OH
Posts: 128
Liked 1 Times on 1 Posts

Default

Quote:
Originally Posted by Walker View Post
Yup. The grey stripe should be to the negative voltage node of the circuit and the non-Grey side connected to the chip. You have it backwards.

Flip it around and it should work perfectly.
The circuit does appear to work better from observing the LED on the SSR. But now I've observed something else odd. It appears that it takes 3-5 minutes for the circuit to get going. When I enable power to it, it does not turn on the SSR at all. A few minutes later and it works fine. If I kill the power and then re-apply the power, the circuit works fine. Do I have a bad capacitor that is taking too long to charge up?
__________________
GregKelley is offline
 
Reply With Quote Quick reply to this message
Reply



Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Show us your element housings/pots. How did you do it? Boerderij_Kabouter Electric Brewing 241 01-23-2014 09:06 PM
Show us your electric brewing rig shroomzofdoom Electric Brewing 167 10-12-2013 06:18 PM
Show me your cheap electrical enclosure Dgonza9 Electric Brewing 34 12-30-2011 03:39 PM
Show me your waterproof heatstick connections CoalCracker Electric Brewing 3 10-27-2010 08:42 PM