Continuously changing the speed of the suction blowers of the medical storage kitchen by using a simple dimmer
Posted: Fri Apr 05, 2024 1:52 pm
by dor123
https://www.youtube.com/watch?v=kHk3_RLgG6E
How it is possible? No variable frequency drive used.
Re: Continuously changing the speed of the suction blowers of the medical storage kitchen by using a simple dimmer
Posted: Fri Apr 05, 2024 4:13 pm
by Ash
The dimmer-like controller reduces the power to the motor, so its available torque drops and it would tend to stall
A motor driving a load with any significant mechanical load would indeed stall
A motor moving air is a bit of special case. The air resistance to the spinning of the fan blade drops very rapidly with the reduced speed (something like to the 2nd or 3rd order iirc), so it doesn't resist much to the motor anymore. As result, the motor can just about keep going in this reduced speed, reduced torque, and very high slip mode