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February 28, 1964 Electronics
 [Table of Contents]
Wax nostalgic about and learn from the history of early electronics.
See articles from Electronics,
published 1930 - 1988. All copyrights hereby acknowledged.
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Admittedly, the only thing
I remember about Gray Code (aka reflected binary) from college courses is that successive count
values change only one bit per increment, saving power in some digital circuits.
The power savings comes from the fact that, especially for CMOS circuits, current
only flows during the transition of a state change from "0" to "1" or from "1" to
"0." Shaft position encoders were and still are a primary application of Gray Code
switching. If the encoder output digital code is going to be used in a binary computation
system, then there is an advantage in generating a direct binary ("natural") count
that does not require a Gray-Code-to-Binary conversion circuit (or software routine).
When the Wayne-George Corporation introduced its paradigm-changing "Natural Code
Non-Ambiguous Optical Encoder" in 1964, those conversion circuits were probably
not simple, compact, inexpensive semiconductor IC's, but more likely vacuum tube
behemoths. Even if IC's were used, the conversion circuit would have been comprised
of quad packs of AND's, OR's, NAND's, and NOR's, not even a single application specific
IC (ASIC). The difference between the two types of encoders is very apparent in
the advertisement. Close inspection reveals that the Gray Code version produces
only one bit change per step whereas the binary version can result in every bit
changing during a single step.
Natural Code Non-Ambiguous Optical Encoder
 Why use a Cyclic-to-Natural Code Converter
when it is no longer necessary?
Now! Natural Code Non-Ambiguous Optical Encoders Exclusive from Wayne-George!
Typical Cyclic (Gray) Code Disk. Output is cyclic or inverted code and must be
converted to natural form for computation.
Wayne-George Natural Code (Binary) Disk. Output is non-ambiguous, natural code
produced directly without conversion from cyclic code.
Only Wayne-George offers a complete line of optical shaft-angle encoders providing
direct, non-ambiguous natural code outputs without code conversion. The new DIGISEC®
and "N" Series DIGISYN® encoders completely obsolete encoders using inverted
or cyclic (Gray) codes and their conversion equipment.
The DIGISEC and "N" Series DIGISYN encoders cover accuracies and resolutions
(per turn) ranging from several minutes of arc to one second of arc. Natural binary,
binary coded decimal or other natural codes are available. Outputs are DC levels
in parallel form and are continuously available. There is no limit to interrogation
rate. Integral code displays can be provided.
High reliability is attained through solid state circuits and long-life incandescent
lamps using low voltages and low power.
Shown is an NB-15 DIGISYN. The "N" Series cover the range from 5 to 17 Binary
Digits.
Shown is 0-19 Digit DIGISEC.
The DIGISEC Series cover the range from 15 to 20 Binary Digits
Wayne-George Corporation
322 Needham Street, Newton 64, Massachusetts (617) 969-7300
Posted December 7, 2023
(updated from original
post on 8/23/2018)
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