Regulating flow small DC pumps

In summary, using a potentiometer or a closing valve to adjust a rate of flow in an aquarium pump is a better option than using a ball valve.
  • #1
Using as an example a 12v pump typical of aquarium, to regulate flow is better to use a potentiometer or a closing valve to affect a rate of flow?
 
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  • #2
Steven Bolgiano said:
Using as an example a 12v pump typical of aquarium, to regulate flow is better to use a potentiometer or a closing valve to affect a rate of flow?
A ball valve will be fantastic.
http://www.industrialvalvestore.com/sites/default/files/004-working-of-ball-valve_0.jpg
 
  • #3
I tend to agree with that. But can someone tell me why a potentiometer isn't an effective way to adjust flow rates. I'm also curious why a brushless motor supposedly cannot be reversed flowed when the current is reversed,... Or at least that's what I've heard
 
  • #4
Steven Bolgiano said:
I tend to agree with that. But can someone tell me why a potentiometer isn't an effective way to adjust flow rates. I'm also curious why a brushless motor supposedly cannot be reversed flowed when the current is reversed,... Or at least that's what I've heard
Well, if there is a non-electric solution, it will always be a better one than the electric one,because electric ones tends to go wrong more often. But regardless of that, controlling a pump with a potentiometer is a great idea.
 
  • #5
Steven Bolgiano said:
I tend to agree with that. But can someone tell me why a potentiometer isn't an effective way to adjust flow rates. I'm also curious why a brushless motor supposedly cannot be reversed flowed when the current is reversed,... Or at least that's what I've heard
A potentiometer can be used for small brushed motors but the potentiometer may have to be rated to dissipate the same power as the motor. Might need a heat sink and cooling.

Brushless motors typically need an electronic means of doing the commutation. So it's not possible to use a single potentiometer in series with the motor to control the speed. However the electronics that does the commutation could be controlled using a potentiometer.

Many brushless motors can be reversed however the way you do it is different..With a small brushed motor you can typically just swap +ve and -ve and it will run backwards (possibly with increased brush wear). With a small three phase brushless motor, as used in model aircraft and model cars, you swap over any two of the three wires going to the motor. Alternatively some brushless motor controllers have a "switch" or link that reverses the commutation order making it spin backwards.

A lot depends what access you have. Do aquarium brushless motors have the controller built in? In that case it might not be possible the get access to the motor windings to swap them over.
 
  • #6
I should also add that the voltage delivered to the pump motor isn't the only thing that determines the flow rate. Changes to the input or output pressure will also change the flow rate.

If you need accurate control measure the flow rate and use a feedback loop to control the motor speed.
 
  • #7
Steven Bolgiano said:
Using as an example a 12v pump typical of aquarium, to regulate flow is better to use a potentiometer or a closing valve to affect a rate of flow?
How accurate do you need it? You also mention reversibility -- is that a design goal?
CWatters said:
If you need accurate control measure the flow rate and use a feedback loop to control the motor speed.
Or use something like a peristaltic pump with stepper motor control (or microstepper motor control):

https://www.graylineinc.com/assets/images/peristaltic-pump-operation.jpg

peristaltic-pump-operation.jpg
 

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1. How do small DC pumps regulate flow?

Small DC pumps regulate flow by using a control mechanism, such as a valve or variable speed motor, to adjust the amount of fluid being pumped. This allows for precise control over the flow rate.

2. What factors affect the regulation of flow in small DC pumps?

Factors such as the size and type of pump, the viscosity of the fluid being pumped, and the power source all play a role in the regulation of flow in small DC pumps. Environmental factors, such as temperature and pressure, can also affect flow regulation.

3. How can I ensure consistent flow regulation in small DC pumps?

To ensure consistent flow regulation, it is important to regularly maintain and calibrate the pump and its control mechanism. This includes checking for any clogs or malfunctions, as well as adjusting the control mechanism as needed.

4. Are there any limitations to the regulation of flow in small DC pumps?

Yes, there are limitations to the regulation of flow in small DC pumps. These pumps may not be suitable for high flow rates or for pumping highly viscous fluids. Additionally, the control mechanism may have a limited range of adjustment, which can affect the precision of flow regulation.

5. Can small DC pumps be used for both low flow and high flow applications?

Yes, small DC pumps can be used for both low flow and high flow applications. However, the pump and control mechanism must be carefully chosen to ensure they can handle the desired flow rate and maintain consistent regulation. In some cases, multiple pumps may be needed to achieve the desired flow rate.

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