[Video] Dual Purpose PWM Project: Stir Plate & PWM Controller - Home Brew Forums
Home Brew Forums > Home Brewing Beer > DIY Projects > Chillers & Stir Plates > [Video] Dual Purpose PWM Project: Stir Plate & PWM Controller

Reply
 
Thread Tools
Old 01-15-2012, 07:33 PM   #1
ahave
Recipes 
 
Jul 2009
Pittsburgh, PA
Posts: 167
Liked 2 Times on 1 Posts



I am calling this project 'done' despite a few glitches. I had a need for a stir plate and also a PWM controller w/SSR for an electric heater (electric smoker for now, HLT down down the road)

Inside the box is a hand-built power supply and 555 timer circuit providing the PWM signal. The selector switch has two purposes:
1) Select the output: When the box is in stir plate mode the SSR will not be active and vice versa.

2) Select the cycle time: The switch will select which capacitors the 555 circuit will use which allows for longer hold times so not to burn out the SSR.

The adjustment knob controls the duty cycle (?), going from near 100% ON to somewhere around 50% ON. The knob provides the same ratio in both modes.

Video shows the box in action w/ a 7/8" stir bar and lamp.



 
Reply With Quote
Old 01-15-2012, 09:41 PM   #2
stlbeer
Senior Member
HBT_SUPPORTER.png
 
stlbeer's Avatar
Recipes 
 
Jan 2008
Fenton, MO
Posts: 963
Liked 37 Times on 36 Posts


Genius!

Nice job.



 
Reply With Quote
Old 01-26-2013, 06:04 PM   #3
fc36
Recipes 
 
May 2010
Chicago, Illinois
Posts: 365
Liked 24 Times on 19 Posts


Any chance we can get schematics or build info?

 
Reply With Quote
Old 02-16-2013, 12:55 AM   #4
ahave
Recipes 
 
Jul 2009
Pittsburgh, PA
Posts: 167
Liked 2 Times on 1 Posts


well, unfortunately I don't really have a schematic. I kinda built it ad hoc, without a circuit design other than what I put together in my head. It uses the standard 555 timer PWM circuit with the exception that one of the capacitors is tied to a double pole, double throw switch. The double pole switch allows me to toggle between different capacitors and at the same time toggle the output of the 555 circuit.

For example: When the switch is in position A, I use a cap appropriate for stir fan control and the other leg is tied to the output of the 555 circuit powers the fan. When the switch is in position B, I use a cap appropriate for heat stick control and the other leg is tied to a SSR controling the 15A 110V line out the back.

I also built my own bridge rectifier powersupply to power everything. Totally not worth it considering you can pick up wallworts pretty easy and for much much cheaper than what it cost me to piece it together.

If you are still interested I can try and put together a schematic of the design.

 
Reply With Quote
Old 02-16-2013, 01:19 AM   #5
nm999
Recipes 
 
Nov 2009
Az
Posts: 93
Liked 5 Times on 3 Posts


Thats brilliant!

I'm interested in a schematic as well.

 
Reply With Quote
Old 09-17-2013, 04:21 PM   #6
fc36
Recipes 
 
May 2010
Chicago, Illinois
Posts: 365
Liked 24 Times on 19 Posts


Quote:
Originally Posted by ahave View Post
well, unfortunately I don't really have a schematic. I kinda built it ad hoc, without a circuit design other than what I put together in my head. It uses the standard 555 timer PWM circuit with the exception that one of the capacitors is tied to a double pole, double throw switch. The double pole switch allows me to toggle between different capacitors and at the same time toggle the output of the 555 circuit.

For example: When the switch is in position A, I use a cap appropriate for stir fan control and the other leg is tied to the output of the 555 circuit powers the fan. When the switch is in position B, I use a cap appropriate for heat stick control and the other leg is tied to a SSR controling the 15A 110V line out the back.

I also built my own bridge rectifier powersupply to power everything. Totally not worth it considering you can pick up wallworts pretty easy and for much much cheaper than what it cost me to piece it together.

If you are still interested I can try and put together a schematic of the design.
Resurrect, yes, please provide us with a schematic. I'm re-interested in this as a side project to my eBIAB that I have planned. It might be nice to utilize the PWM that I already built for my second stirplate to also potentially control a 5500W Camco element with an SSR. I don't need you to draw a perfect diagram, but a back-of-the-envelope drawing would be a great help.



 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
My $15 Solderless stir plate build video. Beer-Baron Chillers & Stir Plates 8 10-26-2011 03:47 AM
My dual flask stir plate build Sorrow Chillers & Stir Plates 2 10-09-2011 04:56 PM
Love TSX-10240 Dual Input/Dual Output Controller Questions....Please Help! Hoppopotomus Fermenters 23 03-29-2011 02:04 AM
Project Box for DIY Stir Plate ToastedPenguin Chillers & Stir Plates 17 12-29-2010 03:18 PM
Stir Plate Video! Yuri_Rage Chillers & Stir Plates 8 08-07-2007 06:18 AM


Forum Jump