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How can I control the speed of this motor? Help a confused dude out? Answered

Hi guys. I want to run this pump to pump water. I also need to control the speed it pumps water at, ideally using a little twisty knob thing. Here's a link to the pump/motor - http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItemVersion&item=271484020192&view=all&tid=1446260598017

I'm a noob at this kind of stuff, but the phrase pulse width modulator or something similar has been mentioned. Is there a cheapo off the shelf thing I can buy, or am i looking at a little bit of building/soldering?

And! But! Also! I'm UK based, so I don't have access to a lot of the great electronics stores my USA bros do. 

Any help greatly appreciated,

Neil

Discussions

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iceng

3 years ago

Hey your motor ebay link is lame.

Why don't you describe the motor.

Is it a DC gear motor or a toy ?

What voltage ?

What RPM ?

What load current ?

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nrobinson1iceng

Answer 3 years ago

Specifications:

Rated Voltage?12V
Rated Current:2.2A
Power:25W
Maximum pressure:0.45Mpa
Flowing Rate:2.9L/Min
Package Size: 19*13*9.5cm
Weight: 0.716Kgs

that any good?

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icengnrobinson1

Answer 3 years ago

Here is a DIY speed control for your RV pump which can certainly handle the current load of your pump motor.

More details are available at

http://pcbheaven.com/circuitpages/PWM_Fan_controll...

to teach you how build this very simple speed control.

Be aware at low speed your motor may overheat if you don't have a fluid pressure cut out ie turn off of the pump 12 volts DC until the pressure drops below the needed pressure.

Happy Building

pwmMotorController555.jpg
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Wired_Mist

3 years ago

You need a simple speed contrroler. Here are a few Ebay links...

http://www.ebay.ca/itm/Regulator-PWM-DC-6V-12V-24V...

http://www.ebay.ca/itm/Motor-DC-6-30V-12V-24V-Max-...

http://www.ebay.ca/itm/12V-40V-10A-PWM-DC-Motor-Sp...

If you want to build your own there a few way to go about it... Do you have any interest in learning to program a micro controller like an Arduino?

Otherwise...

look up "LM317" schematics in Google. it is an adjustable voltage regulator with lots of documentation ! Unfortunately the lm317 is limited to 1.5A so directly replace it with it's bigger brother the LM1084 (it's a direct replacement) Also this regulator requires a minimum 1.2V more then what will be supplied to the pump. So if you want to run your pump at 12v you need a 13.5V supply(or just run you pump at 10.8 V that should still work fine :)

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nrobinson1steveastrouk

Answer 3 years ago

I did see that earlier, but was a bit worried because it says 10Amps and my pump is 2Amps.. what effect will that have?

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icengnrobinson1

Answer 3 years ago

Steve's recommendation to you is top notch. Your grounding in electricity is very sparse...... Consider water pressure as voltage and water flow as amps of current.

Now imagine a farmers water tank being used to water a lawn, it would run out of current in a morning BUT if there is a hill lake it could supply current for days.

So a large current supply ability is a desirable quality in a power supply.

waterAnalogy.png
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steveastrouknrobinson1

Answer 3 years ago

10 A is a MAXIMUM current it can supply, it will be fine here, running on only 2.

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seandogue

3 years ago

To control the flow, a flow regulating valve is probably the easiest, regardless of the pump you have

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nrobinson1seandogue

Answer 3 years ago

I have done that before, but I think it burned my last pump out - hence why this time I want to control the motor speed..