Speed controller for 1/6th HP shaded pole motor.

[fastline]

Got in a hurry and bought a cheap "speed controller" on ebay. China junk.... Basically a voltage chopper, NOT variable frequency as far as I can tell. Advertised as 40-240V but I guess that in the variable outputs.... I did not even put on the scope because there are not even any ICs on the board so I assume just chopping voltage and amperage seems to follow in a linear fashion.

What I need is a good speed control! I guess a VFD but for 1/6th HP? We are at 3.5A at 120V....

Ideas, thoughts?

 

[Les Jones]

You cannot blame the fault on the speed controller. You read (Or should have read what method it used.) so it is your fault that it did not do what you want. It is not possible to control the speed of a shaded pole motor much away from its design speed. The only type of application I have seen where a shaded motor speed is controlled is when driving a fan where the required torque drops very much as the speed is reduced. This is normally done by effectively reducing the voltage with resistors, phase angle control or tapped windings. I have never seen a shaded pole motor as large as 1/6 HP. A VFD would not solve your problem. Also VFDs are normally made for 3 phase motors. If you want good speed control then a 3 phase motor with a VFD or a DC motor (Permanent magnet or shunt wound) with a DC speed controller is the best way to go.

Les.

 

[MaxHeadRoom78]

I agree for that size of motor it may be worth scrapping the AC motor and using a small DC brushed motor, the PWM controllers are $5.00 on ebay, or simple 555 circuit and Mosfet will do it.
Max.

 

[Tony Stewart]

You can easily vary the speed with a Triac controller but actual speed is dependant on torque profile and load profile, so it will not be well regulated.
If you want accurate speed control, then DC motor is best or VFD.

 

[MaxHeadRoom78]

Got in a hurry and bought a cheap "speed controller" on ebay. China junk.... Basically a voltage chopper, NOT variable frequency as far as I can tell. Advertised as 40-240V but I guess that in the variable outputs.... I did not even put on the scope because there are not even any ICs on the board so I assume just chopping voltage and amperage seems to follow in a linear fashion.
What I need is a good speed control! I guess a VFD but for 1/6th HP? We are at 3.5A at 120V....
Ideas, thoughts?

I suspect also it is not shaded pole? If so a Triac controller would normally work, if it has a capacitor, these do not take well to variable speed, a Universal motor off of a small appliance should however.
Max.