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Author Topic: HELP: DC MOTOR & DRIVER  (Read 1891 times)

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Satra

• Beginner
• Posts: 1
HELP: DC MOTOR & DRIVER
« on: July 29, 2015, 07:52:53 AM »
Hey Guys,
M a beginner and I want to connect a dc motor to the blades of table fan.
All I know is I have a 12V,1A power supply and I want to vary the speed of that motor so I've connected a pot(10k) at the output.
Can anyone tell which motor,motor driver  should I use and where will I get it online?

cyberjeff

• Full Member
• Posts: 114
Re: HELP: DC MOTOR & DRIVER
« Reply #1 on: July 29, 2015, 11:23:33 AM »
It's common for beginners to have not researched enough before asking, so...

http://arduino-for-beginners.blogspot.com/2011/03/controlling-12v-dc-motorfan-with.html

(among other articles...)

That is assuming you wish to use a microcontroller which is what we robot boys and girls would do.

Or you could just buy it all in one piece on Ebay or Amazon.

There are all sizes and kinds of fans:

https://en.wikipedia.org/wiki/Mechanical_fan

So, give it a bit more thought and get back to us.

ProgressiveAutomations

• Jr. Member
• Posts: 10
• Experts in Linear Motion
Re: HELP: DC MOTOR & DRIVER
« Reply #2 on: August 12, 2015, 06:46:00 PM »
Connecting a pot to a motor will vary the speed, but you're burning up lots of energy in the potentiometer.  If you get to a sizable motor (even a 1 amp draw is getting sizeable) you'll be looking at tons of energy waste.

The best way to control the speed of a motor is with an H bridge and a PWM signal.  The H bridge acts as a switch that can turn power to the motor on and off, as well as reverse direction.  The PWM signal commands the speed that the switches turn on and off, determining the speed.  PWM runs at thousands of cycles per second, so the motor runs smoothly.  For example, if you turn the switches on for 25% of the time, off for 75%, the motor will run at 25% speed.

H bridges and motor controllers can be found at many electronics stores, including ours.
Experts in Linear Motion