how does ac drill speed control work?

[bran1har]

Ok, so you know on a handheld corded drill how the more you depress the trigger, the faster the motor will spin. How does that system work. I always thought you couldn't control the speed of an ac motor it was set by the frequency of the power line 60hz. Anyone know anything about this subject?

 

[rlitman]

You are thinking of an A/C induction motor.
A drill generally uses a "universal" motor with brushes.

 

[Steevo]

When you squeeze the trigger, the framistat is moved inside the inducinating coil, which generates the inversion frequency needed to initiate amplitude in the coil windings. This, in turn, sets up a reversing flux in the magnetic fields of the armature, which translates into rotational force. This rotational force is transferred through the planetary gears to the thing that holds your dull spiral pointy things.
Many people assume that fully depressing the trigger increases the rotational speed, when it actually does not. The trigger actually acts as a brake release by pushing against the spring that is squeezing down on the disc attached to the planetary assembly, much like a disc brake on a car. The harder you squeeze, the less this brake squeezes the disc, so the faster the drill spins. The main issue with this design is that when you take your drill motor south of the equator, you have to remember that the entire process reverses, your drill rotates the other way, and you need left handed bits.

 

[PT Doc]

When you squeeze the trigger, the framistat is moved inside the inducinating coil, which generates the inversion frequency needed to initiate amplitude in the coil windings. This, in turn, sets up a reversing flux in the magnetic fields of the armature, which translates into rotational force. This rotational force is transferred through the planetary gears to the thing that holds your dull spiral pointy things.
Many people assume that fully depressing the trigger increases the rotational speed, when it actually does not. The trigger actually acts as a brake release by pushing against the spring that is squeezing down on the disc attached to the planetary assembly, much like a disc brake on a car. The harder you squeeze, the less this brake squeezes the disc, so the faster the drill spins. The main issue with this design is that when you take your drill motor south of the equator, you have to remember that the entire process reverses, your drill rotates the other way, and you need left handed bits.

Excellent explanation.

 

[bran1har]

thanks for the explanation, very helpful. south of the equator reverses a motor?

 

[gatchel]

Lol!

 

[rlitman]

Excellent explanation.

I feel like we need a link to the Turbo Encabulator here. Nice one.

 

[ForceFed70]

Most power tools use pulse width modulation to controll motor speed. But Steevo's explanation is more ****.

 

[kbs2244]

http://en.wikipedia.org/wiki/Pulse-width_modulation

 

[6768rogues]

When you squeeze the trigger, the framistat is moved inside the inducinating coil, which generates the inversion frequency needed to initiate amplitude in the coil windings. This, in turn, sets up a reversing flux in the magnetic fields of the armature, which translates into rotational force. This rotational force is transferred through the planetary gears to the thing that holds your dull spiral pointy things.
Many people assume that fully depressing the trigger increases the rotational speed, when it actually does not. The trigger actually acts as a brake release by pushing against the spring that is squeezing down on the disc attached to the planetary assembly, much like a disc brake on a car. The harder you squeeze, the less this brake squeezes the disc, so the faster the drill spins. The main issue with this design is that when you take your drill motor south of the equator, you have to remember that the entire process reverses, your drill rotates the other way, and you need left handed bits.

I read that and now I have an urge to sit on the toilet.