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Topic: Control single phase motor pump with producing pwm in atmega2560 (Read 135 times) previous topic - next topic

setiawanph

Hello. I'm a newbie for AC motor project with Arduino. I'm in progress of making inverter to control my motor pump with changing frequency in inverter. Now, I need a code to change the frequency in motor while the temperature sensor goes up and down. I've already read the article titled PWM frequency in these sites

https://github.com/fizcris/PWM_frequency_Arduino_change
https://playground.arduino.cc/Code/PwmFrequency

However, I'm doubtful using those codes in articles to control my pump motor. I read that the setPWMFrequency() would change the base frequency of arduino.

So, my question is:
1. Will it set as base pwm frequency after I code my arduino to change the frequency?
2. Can I find another site whose doesn't have to change the base pwm frequency, and adjustable to change?

Thank you for your attention.

MarkT

You need to learn a lot more about motor control I think.  No, the PWM frequency has nothing
to do with motor speed. 

What is this AC motor?  Is it three phase induction?  Or os it a synchronous motor?  Where's the
datasheet?

Note most cheap AC motors are single phase induction and not amenable to speed control, or only
in a very limited way.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

setiawanph

The motor is just single phase. I didn't own the datasheet because it was difficult to download. Also, the specification is just for the pump and recommended electricity setting.

I found another code to change the speed in motor. But, I'm not confident with this.
https://playground.arduino.cc/Code/FrequencyTimer2

MarkT

As I said most single phase motors are _not_ amenable to speed control.  V/f is the best method, but
shaded poles and phasing capacitors are tuned to a particular frequency so don't handle changes in f
well.

If you get it wrong the motor might stall and the current through the windings can rise lots and cook
the motor.  Some motors can handle such stalls, others can't - that's why the datasheet is important it
will show the current/torque/slip-rate profile.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

setiawanph

This is my inverter to control the motor. And I have one signal generator to control the motor voltage. My lecturer recommended arduino as the signal generator and can use timer interrupt to generate variation of frequency, as I know. But, I still have doubt thinking and trying another way to make astable frequency. So, how If I create a signal generator from arduino?

Oh. The specifications of motor are 125 Watt and need 220V and 0.94 Ampere to generate the motor. And It's brushed motor.

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