Pwm motor makes a buzzing noise

[skmdmasud]

yep it's very strange one moment it's cool next moment it explodes. i am afraid to put a bigger diode cuz if the same happens with it may catch fire... i think i found the write diagram, i will post it tomorrow.
regards.

 

[skmdmasud]

It's a very strange arrangement if some 'settings' (?) change the polarity

by setting i mean the front panel switches like fresh air, recycle air, air to the feet, etc...

 

[skmdmasud]

Got the wiring diagram. I did some labeling to reflect the current situation.

 

[alec_t]

That switching arrangement does not change the polarity of the voltage applied to any of the motors.

 

[skmdmasud]

That switching arrangement does not change the polarity of the voltage applied to any of the motors.

Yep that true. May be my diode was not good. Can a diode just die and behave like a closed circuit. After studying the diagram i feel more confident.

What happens if my Drain and Source is connected the other way round?? cuz i connected the Drain and Source blindly where the NAVY BLUE Point marking are in the diagram.

 

[alec_t]

Can a diode just die and behave like a closed circuit

Yes. But there's always a reason for it dying. Wrong polarity, excessive current or excessive voltage will kill it.

What happens if my Drain and Source is connected the other way round?

You stand a good chance of destroying the FET.

i connected the Drain and Source blindly

You should always download the datasheet for any electronic device and check the pinout before connecting it up.

 

[skmdmasud]

Yes. But there's always a reason for it dying. Wrong polarity, excessive current or excessive voltage will kill it.
You stand a good chance of destroying the FET.
You should always download the datasheet for any electronic device and check the pinout before connecting it up.

I read the datasheet its the wire in the blower switch which was unknown to me.

 

[ronv]

The diode may not have been big enough. What current does your motor draw. The diode needs to be about that size. (50% of motor current plus margin)

 

[skmdmasud]

The diode may not have been big enough. What current does your motor draw. The diode needs to be about that size. (50% of motor current plus margin)

Hi..
the fuse for the blower motor is rated at 40A, this means i should get a diode which can handle 20A.

 

[ronv]

It doesn't look like a 40 amp motor, but.......

maybe something like this with a little heat sink.

https://www.mouser.com/ds/2/427/94167-48151.pdf