DC Basics - wiring 3position Switch, Potentiometer, Battery, Load (6v pump)

Thread Starter

sbolgiano

Joined Aug 28, 2018
3
I figured out how to wire potentiometer/battery/pump and I figured out DPDT 3 position switch/battery/pump..... but I've really confused myself on combining all four elements.
I am definitely a beginner. Can someone send me an idiot proof diagram?
Thanks in advance,
Steven
 

Thread Starter

sbolgiano

Joined Aug 28, 2018
3
What exactly are you trying to do? Can you show us the schematic you have so far?
Hi!
I need to use a small DC pump in a project, whose speed and direction can be adjusted. (attached are the components).
I'm familiar with how to wire the three position switch itself , but the Pot I only think I do, because I don't know where the ground connects if the load (pump) is made of plastic.
What I need is a kindegarten level illustration of how to combine the switch, Pot, battery, and pump.

Thanks!
Steven
 

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LesJones

Joined Jan 8, 2017
2,347
You can't reverse the direction of flow on that pump for two reasons.
1/ It is a centrifugal pump so even if you could reverse the direction of rotation of the motor it would not reverse the flow. ( It may even pump waiter in the same direction if the motor was reversed but not very well.)
2/ It is a brushless motor so reversing the polarity of the power supply would not reverse the direction of rotation of the motor. It may just not work with reversed power polarity or it may destroy the electronics inside the brushless motor. (It would depend on the design of the electronics.)

Les.
 

blue_coder

Joined May 7, 2016
28
Being a pump engineer, I can confirm what Les says that you get around 60% flow in the same direction when you run a centrifugal pump backwards.
I'm also thinking that 6v on a 12v pump may not be an excellent idea?
And that pot looks like a 1/2watt, so possibly not ideal for directly controlling a 5 watt motor, never mind whether it is as a series resistance or as a potential divider.
Could you provide details of what you are trying to achieve, so that we can maybe point you in the direction of the parts you should be using?
 

Thread Starter

sbolgiano

Joined Aug 28, 2018
3
Thanks! As an old Farmer told me once: " Son not only do you not know the answers, you don't know the questions!"
The project is one in a series of parabolic reflective water heating systems. Some have been large, this one is small.
The core goal as far as the forum question, is adjusting flow of the circulated water. Reversing flow would have allowed me to observe some minor concerns, but that's eliminated from my agenda.
So I'd like to wire that Pot correctly to adjust flow rate and observe what reduced rate is needed to maintain delivery temps 100C+.
HOWEVER, your comments have me second guessing if it's better to control the rate in this case with a ball valve shutting down, rather than a potentiometer on an electric pump.

Your correct on the 12v/6v issue. I was actually aware of that, but must have had a "Senior Moment" when writing.
I'm almost 70, started using three-dimensional design drafting in 1986. My last project designed was a quarter million gallon anaerobic digester taking chicken shit to electricity.
And you can bet I avoided pump science, electrical, I&C, and thermodynamics, like the plauge. I relied heavily on a talented team.
Now retired, with my 3d Printer in hand, and no team of specilistsI suddenly and belatedly have a morbid facination with DC electronics and thermodynamics.

So for a rank beginner, who is in it for fun not career, what book or resource do you suggest to minimize forum questions I can learn or research first?
ApoliApol for the long post. This one will be the exception.
 
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