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Topic: 0-12V Analog output (Read 180 times) previous topic - next topic

Buchp

Hello,
I have a small pump that I'd like to controll using an Arduino Uno just as a experiment. The pump only needs 12v and I plan to controll the speed by adjusting the voltage from 0V to 12V and I was wondering how I should go about doing this. I have a 12V powersupply and thought of using and DAC to output 0-5V and then using an op-amp to turn this into 0-12V, but I'm unsure about how I'm supposed to go about doing this. Any suggestions?

neiklot

PWM the gate of a mosfet?






Grumpy_Mike

Quote
thought of using and DAC to output 0-5V and then using an op-amp to turn this into 0-12V
What DAC?
Most Arduinos do not have one. They have a PWM pin that is set by the wrongly names analogWrite function.

Controlling a motor by simply changing the voltage is a bad idea because the torque drops off rapidly with voltage so PWM is used instead as it has bunch better torque at lower speeds. That is what the reply above is showing you. Consider no other alternative methods of control.

wvmarle

Many pumps are brushless DC motors. They may not react well to PWM: not at all, or resulting in weird behaviour. Most brushless DC motors can not be speed controlled, those that can will have a separate speed signal input.
PWM is great for controlling the speed of brushed DC motors.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

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