Motor Encoder

[SuperMiguel]

What are motor Encoder for? whats the function of it?

[Sionyn]

ah that a rotary encoder

dc motor i take it

http://en.wikipedia.org/wiki/Rotary_encoder

[Lance]

That's pretty much it. They're used for tracking the rotation of a motor.

[SuperMiguel]

why would u want to track it?

[ndictu]

You have a motor driving your robot and you want to go 1 meter forwards and then turn 45 degrees. You need some kind of feedback because the actual time you need to keep motors on will change based on battery level, weight, surface etc.

[SuperMiguel]

gotcha

[tecman]

Encoders are used  for measuring the angle (aka distance) on motors, but on certain types of brushless AC motors, they are used as well to control commutation.  Adding an encoder to a vector drive can improve low speed operation and decrease coging.  AC servo motors (permanent magnet types) also use encoders for precision movements and commutation.

paul

[nyo]

Correct me if I'm wrong, but the simplest data it can give you is rpm

[bilko]

Usually, you can get position, direction, speed.
A pc mouse (with roller ball) has two built in to control the cursor

[Mechatrommer]

Correct me if I'm wrong, but the simplest data it can give you is rpm

http://en.wikipedia.org/wiki/Rotary_encoder
absolute encoder is much more expensive than relative encoder, so i never work with absolute type. relative encoder you can use quadrature (binary encoding) or incremental, from there you can postprocess the parameters for rotation (relative to previous position/parameters) such as direction, angle, rate of change (speed or acceleration).