Hello Guys ,
im a mechanical engineer and i need some help on controlling a pwm that control a dc fan motor. The pwm has three wire +12v,-12v,and signal. The working concept of pwm is based on ground switching the signal wire. so im planing to ground switching the signal through arduino and mofset. from what i know , the mofset has a gate voltage to trigger it. so i want to know does the gate voltage affect the duty cycle???
lets take example:
analogWrite(pin9, 51);
51=20% duty cycle which equals to 1v
but my mofset only trigger at 2v so does that mean i cant run the pwm at 20 duty cycle?
root-shell:
Hello Guys ,
im a mechanical engineer and i need some help on controlling a pwm that control a dc fan motor. The pwm has three wire +12v,-12v,and signal. The working concept of pwm is based on ground switching the signal wire. so im planing to ground switching the signal through arduino and mofset. from what i know , the mofset has a gate voltage to trigger it. so i want to know does the gate voltage affect the duty cycle???
I am a bit confused here you are controlling a "PWM" that controls a dc fan motor? "PWM" stands for pulse width modulation, it is not an object but a method of applying power in pulses.
Do you have a speed controller that you would like to control the speed of a fan with. This speed controller might take a pwm signal to control its duty cycle or pwm to the motor.
The first post seems to imply there is a control box or speed controller or something that is attached to the fan motor. We would need to know more about this thing ( and the motor) to really give useful advice.
@alka
Sorry do confusing you . you are right im using speed controller which use pwm to control the motor. Basically the speed controller is controlled by a signal wire that has 11v+ on it and it is required to be grounded by pwm "ground switching" in order to make the motor work .
