Home Brew Forums > Home Brewing Beer > DIY Projects > Chillers and Stir Plates > Simple PWM Stirplate Controller
Reply
 
Thread Tools
Old 12-01-2012, 12:27 AM   #61
Jackjama
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2012
Location: Houston, Tx
Posts: 59
Likes Given: 5

Default I need my fan to go slower

I built this on a bread board using the values on the front page. My fan goes from a medium speed to a fast speed. I need to get it to go slower. Either i have hooked something up wrong or i need some different values on some of my components.

I have double checked the drawing and i fell like everything is connected correctly. I used the values on the drawing. The only doubt i have is the capaciter. The capaciter has a long wire and short wire. I hooked the short wire to ground and the long wire to terminal 6. Is this correct? The data sheet said the long wire is positive.

I am guessing i need to go up on either r2 or c1. Any suggestions?


Jackjama is offline
 
Reply With Quote
Old 12-01-2012, 06:49 AM   #62
nmfree
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2008
Location: , Wisconsin
Posts: 63
Liked 15 Times on 10 Posts
Likes Given: 216

Default

Quote:
Originally Posted by Jackjama View Post
The only doubt i have is the capaciter. The capaciter has a long wire and short wire. I hooked the short wire to ground and the long wire to terminal 6. Is this correct? The data sheet said the long wire is positive.
That's correct.

Quote:
Originally Posted by Jackjama View Post
I built this on a bread board using the values on the front page. My fan goes from a medium speed to a fast speed. I need to get it to go slower. Either i have hooked something up wrong or i need some different values on some of my components.

I am guessing i need to go up on either r2 or c1. Any suggestions?
Before you start changing anything, I'd suggest you finish mocking up the whole thing (glue your magnet to the fan, etc.) and actually try it out with your flask/jar/vessel and your stir bar. Right now with no load the fan might seem to be spinning too fast, but the added mass of the magnet, the stir bar, and the liquid in the flask will help slow the motor down.

If after testing your set up the fan is still spinning too quickly, then you can try adding resistance in series with R2 or try Kaiser's modification a few posts up.


__________________
Home of the world's first Yoctobrewery- brewing beer one sip at a time.
nmfree is offline
 
Reply With Quote
Old 12-01-2012, 01:33 PM   #63
Jackjama
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2012
Location: Houston, Tx
Posts: 59
Likes Given: 5

Default

Thanks i will finish building before i do anything.
Jackjama is offline
 
Reply With Quote
Old 12-03-2012, 02:56 AM   #64
Kaiser
Feedback Score: 0 reviews
 
Kaiser's Avatar
Recipes 
 
Join Date: Nov 2005
Location: Pepperell, MA
Posts: 3,904
Liked 121 Times on 73 Posts
Likes Given: 4

Default

changing the way the capacitor is charged and drained is key to be able to change the pulse width from 0 to 100%. I ended up building it like this:



you need one more diode but don't need R1.
It works like a charm.

Kai
Kaiser is offline
nmfree Likes This 
Reply With Quote
Old 12-04-2012, 01:37 PM   #65
Jackjama
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2012
Location: Houston, Tx
Posts: 59
Likes Given: 5

Default

I will give this a try. I currently have my stirplate to where it goes slow enough to use. However it does not turn off completely.

What is the purpose of sinking both the .1 and 22 mf capacitors from the source to ground?
Jackjama is offline
 
Reply With Quote
Old 12-05-2012, 03:54 AM   #66
Kaiser
Feedback Score: 0 reviews
 
Kaiser's Avatar
Recipes 
 
Join Date: Nov 2005
Location: Pepperell, MA
Posts: 3,904
Liked 121 Times on 73 Posts
Likes Given: 4

Default

Quote:
Originally Posted by Jackjama View Post
What is the purpose of sinking both the .1 and 22 mf capacitors from the source to ground?
That's to stabilize the input. You may not need it. RocketMan mentioned this in one of his posts.

Kai
Kaiser is offline
 
Reply With Quote
Old 12-06-2012, 09:00 PM   #67
DSmith
Feedback Score: 0 reviews
Recipes 
 
Join Date: Sep 2011
Location: Robbinsdale, MN
Posts: 793
Liked 72 Times on 60 Posts
Likes Given: 12

Default

These are avaiable for $10 shipped on ebay:

http://www.ebay.com/itm/12V-40V-10A-...item1c2925822e

I bought the one in the link above, in a build with a 18V power supply, 40V fan & (2) 20lb pull disc magnets.

Click image for larger version

Name:	IMG_1942.jpg
Views:	252
Size:	42.5 KB
ID:	87223
Click image for larger version

Name:	Improved Stirplate_Pic 1.jpg
Views:	248
Size:	36.9 KB
ID:	87226
DSmith is offline
 
Reply With Quote
Old 03-28-2013, 05:51 AM   #68
tommyturbo
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2013
Posts: 2
Default

how would you go about adding a power supply to this project?
tommyturbo is offline
 
Reply With Quote
Old 04-11-2013, 02:59 AM   #69
tommyturbo
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2013
Posts: 2
Default

well, heres my take on it so far...


Let me know what you think
tommyturbo is offline
 
Reply With Quote
Old 04-02-2014, 05:11 PM   #70
cheesenips
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2014
Location: Vancouver, BC
Posts: 5
Likes Given: 3

Default

Bumping this old thread, hopefully someone's can help me out.

The mosfet linked by op is not made anymore, so does anyone have a part # for an equivalent?


cheesenips is offline
 
Reply With Quote
Reply


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
And one more DIY stirplate... -TH- Chillers and Stir Plates 9 01-03-2012 09:05 PM
Inline Thermometer Build - 3/4" - Simple Simple passedpawn Kettles, Mash Tuns, & Hot Liquor Tanks 22 07-21-2011 11:42 AM
DIY Stirplate help chode720 Chillers and Stir Plates 19 03-02-2011 04:19 AM
blender stirplate anderj Chillers and Stir Plates 3 02-04-2008 05:54 PM
Simple Stirplate DRAGGER Chillers and Stir Plates 2 01-05-2008 11:28 PM


Forum Jump

Newest Threads

LATEST SPONSOR DEALS