33,136
edits
X381: Difference between revisions
→Rotary Optical Encoder
| Line 80: | Line 80: | ||
It is possible that they are energized independently to select different tracks on the encoder disk, | It is possible that they are energized independently to select different tracks on the encoder disk, | ||
e.g., the "SEC"-mode numeric encodings versus the "Hz"-mode numeric encodings. | e.g., the "SEC"-mode numeric encodings versus the "Hz"-mode numeric encodings. | ||
Each photodetector has two strands of optical fiber entering it, | |||
from separate tracks on the encoder disk. | |||
It is possible that the position of the SEC/Hz knob determines which of the two bulbs will be energized, | |||
thus selecting one or another subset of the tracks on the encoder disk. | |||
Feeding pairs of fiber strands into a single photodetector serves as a logical OR. | |||
Viewed from a modern perspective, the encoder disk is two ROMs driven by the same address lines, | |||
with the two light bulbs serving as chip select lines. | |||
==Motorized TIME/DIV== | ==Motorized TIME/DIV== | ||