Peristaltic pump: flow control - Home Brew Forums

Register Now!
Home Brew Forums > Home Brewing Beer > Electric Brewing > Peristaltic pump: flow control

Reply
 
Thread Tools
Old 02-06-2012, 08:09 PM   #1
jfsp
Recipes 
 
Sep 2011
Montreal, Quebec
Posts: 40
Liked 1 Times on 1 Posts



Simple question : How would you control the flow of a DIY peristaltic pump when you don't want to run it at max speed ? I see 3 choices :

1) regulate/reduce the voltage to get lower speeds (would that work with an AC motor or would I just loose torque?)

2) run at full voltage, but pulse the current (x times per seconds)

3) run at full voltage, full current (max speed), but take breaks every z seconds (for example, run 5 seconds, stop for 5 seconds ...)

Lets assume stepped motors are not an option.

 
Reply With Quote
Old 02-07-2012, 01:46 PM   #2
bdjohns1
Recipes 
 
Dec 2011
Sun Prairie, Wi
Posts: 315
Liked 35 Times on 33 Posts


Quote:
Originally Posted by jfsp View Post
Simple question : How would you control the flow of a DIY peristaltic pump when you don't want to run it at max speed ? I see 3 choices :

1) regulate/reduce the voltage to get lower speeds (would that work with an AC motor or would I just loose torque?)

2) run at full voltage, but pulse the current (x times per seconds)

3) run at full voltage, full current (max speed), but take breaks every z seconds (for example, run 5 seconds, stop for 5 seconds ...)

Lets assume stepped motors are not an option.
4) Variable frequency drive. This is how AC operated motors in industrial applications have their speed modulated. Instead of changing the voltage, you change the frequency of the electricity from its usual 60Hz to something else. That changes the rate of rotation of the motor. These are generally used on 3-phase motors.

Looks like automationdirect.com can put you in a 1/4HP VFD for $100.

 
Reply With Quote
Old 02-07-2012, 01:49 PM   #3
broadbill
Recipes 
 
Aug 2007
Southern Maine
Posts: 3,919
Liked 530 Times on 357 Posts


Quote:
Originally Posted by bdjohns1 View Post
Looks like automationdirect.com can put you in a 1/4HP VFD for $100.
Probably not a viable option, since DIY pumps are typically done to avoid shelling out $150 for a ready-made pump.

 
Reply With Quote
Old 02-07-2012, 04:57 PM   #4
JRems
Recipes 
 
Nov 2010
Mahopac, NY
Posts: 2,221
Liked 60 Times on 52 Posts


Look into a router speed control. I think it's more of a pwm and pulses the power. I used one to control the speed of a fan before and worked pretty good. Harbor freight has one for I think $20.

 
Reply With Quote
Old 02-07-2012, 11:43 PM   #5
yjfun
Recipes 
 
Jun 2010
Arlington, Washington
Posts: 225
Liked 2 Times on 2 Posts


I tore apart an old treadmill and am using the controller and motor from that to build mine. The motors are usually 90-120 volt DC and all the controls are already there for the speed control. Only cost me $10 on craigslist for the whole thing. The controllers are usually PWM's IIRC so there isn't any loss of torque like you would get using a rheostat. I'll hopefully have mine built in a couple of weeks and then post some pictures.

 
Reply With Quote
Old 02-08-2012, 12:37 AM   #6
moparx12
Recipes 
 
Apr 2010
charlotte
Posts: 193

another option for an AC motor is this little device that hooks on to any standard SSR. Supposedly it is better than frequency control for some motors that might otherwise overheat with that kind of control.

like $40: http://www.nuwaveproducts.com/ssrman-1p.htm

 
Reply With Quote


Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
My new Control Box... Dgonza9 Electric Brewing 19 11-09-2012 04:00 PM
Pump control Brewer Gerard Electric Brewing 10 11-28-2011 04:48 PM
What happens when you use your pump to shoot water at your control panel bf514921 Electric Brewing 40 11-25-2011 09:32 PM
Control Box dhempy Electric Brewing 0 07-13-2011 01:13 AM
Can I use this pump? acefaser Electric Brewing 5 04-25-2011 01:09 PM


Forum Jump