synchro mechanism

Incremental encoders are position feedback devices that provide incremental counts. Incremental encoders have only a single band consisting of alternate transparent and opaque sectors. As the encoder turns, the photo sensor sends a quasi-sine wave to a Schmitt trigger, which transforms this into a sharp square wave, a series of pulses. These go to an UP/DOWN counter, whose count represents the encoder position. Commercially available incremental encoders typically give from 200 to high as 5000 pulses per turn.

Compared to coded pattern encoders, incremental encoders have four main advantages:

1. They are simpler and less expensive
2. They need no decoding circuits, only a counter.
3. Their range is only limited by the counter capacity. Additional encoder with step down gearing is used to increase the range that can be covered.
4. The measurement origin can be chosen at any point by resetting the counter (floating zero).

Drawback:

1. Incremental encoders do not measure absolute position, only incremental changes. Therefore, any mistake in the count is carried along to all subsequent counts.

Applications

• Precise angle measurement
• RPM or direction of rotation measurement
• X/Y positioning tables
• Positioning in handlings-systems
• I