H-38-11 Bourns Inc., H-38-11 Datasheet - Page 17

• Manufacturer Part Number: H-38-11
• Description: HDWR NUT MOUNTING FOR ECW ENCODR
• Manufacturer: Bourns Inc.
• Type: Mounting Nutr
• Series: Hr

Specifications of H-38-11

• Mounting Hole Size: 9 mm
• Features: Hardware indicated by shaded area is normally supplied with unit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: ECW1DB24BC0024 - ENCODER DIGITAL CONT 24 CPRECW1JB24BC0024 - ENCODER DIGITAL CONT 24 CPR
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

16
Encoders
Types of Output Signals
There are two basic types of encoder output signals:
incremental and absolute. The incremental signal
consists of two phase-shifted, square-wave signals.
The phase shift is required for recognition of the
direction of rotation. The absolute signal, also
known as Gray Code, consists of discreet coded
binary values and may be from 4 to 16 bits wide. In
application, absolute encoders are required if a
particular setting must be recognized and available
after a power down of the system. All other
applications can use an incremental encoder.
Speed of Rotation
Contacting encoders have a
higher sensitivity to speed of
rotation or revolutions per
minute (RPM). On the other
hand, non-contacting encoders
can be rotated at high speeds. Most
contacting encoders begin to skip counts when the
shaft is rotated in excess of 100 RPM, while non-
contacting encoders fitted with ball bearings can be
rotated at speeds up to 3000 RPM.
Rotational Life
Contacting encoders have a limited rotational life
due to wear on mechanical contact components used
to create the signal output. In general, contacting
encoders have a rotational life below 100,000 cycles.
On the other hand, non-contacting encoders can
endure rotational life in excess of 1,000,000 cycles.
Non-contacting encoders are theoretically limited by
the wear in bearing surface of the
bushing or ball bearings holding the
shaft in place. Typical cycle life
expectancy is 10 million without
ball bearings and 200 million
with ball bearings.
Switching Capability
Encoders are frequently used in switching
applications where each discreet binary
number in the output signal is
recognized as a specific instruction
or setting for the digital system. In
such cases, the system must
recognize the position of the encoder
after power down of the system. For those
applications, encoders such as Bourns® Model EA
Absolute Contacting Encoder (ACE™) are the
perfect solution. Incremental contacting encoders
can also be used in such applications. However, the
designer must make additional software and
hardware provisions for retaining the encoder
position in a non-volatile memory.
Another frequently used option available in many
encoder models is the momentary push switch. This
type of switch is typically used to drive menu
selection in a digital display. Bourns offers the model
EP and PEC series encoders with momentary push
switch options to suit your application.
Additional information on performance
characteristics and applications is contained in the
“Application Notes” section of this guide.