54M-1BB-1AL Grayhill Inc, 54M-1BB-1AL Datasheet - Page 5

• Manufacturer Part Number: 54M-1BB-1AL
• Description: 54M30-01-1-03N & 01-1-12N-C T, Military 85&deg
• Manufacturer: Grayhill Inc

Specifications of 54M-1BB-1AL

• , 30°: , 1 Deck, 1 Pole/deck, 2 Positions/pole, Non-shorting & 1 Deck, 1 Pole/deck, 2 Positions/pole, Non-shorting, 54M-1BA-1BA
• Lead Free Status / Rohs Status: Compliant

F-5
Thus, the switch runs “hot”, increased
mechanical wear and contact erosion result.
Your application probably requires manual
operation of the switch with an attendant low
duty cycle. If so, you can usually expect much
longer switch life than is shown by the
accelerated life laboratory life tests.
Conclusion
Remember, load and life ratings are based on
manufacturers’ selected references. They
include accelerated life tests and an arbitrary
set of application parameters and failure criteria.
These parameters and criteria may not always
fit your application.
Then how do you know if a switch will give
reliable performance in your application?
How do you know if it will last the life of your
equipment?
Ask the switch manufacturer. Grayhill, and most
other reputable manufacturers have compiled
vast quantities of test data. We are in a position
to give a good estimate of a switch’s performance
in many nonstandard applications. You should
provide the following data:
Expected Life:
Load:
Operation:
Application:
Environment:
Failure Criteria:
With this information, we can usually estimate if
a given switch is suitable for your application.
Grayhill, Inc. • 561 Hillgrove Avenue • LaGrange, Illinois
voltage, current, power
factor, and frequency
manual or mechanical,
duty cycle
type of equipment
altitude,
temperature
relative
corrosive atmosphere,
shock, vibration, etc.
end of life contact
resistance, dielectric
strength,
resistance, etc.
in number of cycles
Rotary Switch Engineering Information
insulation
humidity,
ambient
range
SOLDERING
What causes failure in a new switch after it has
been installed? The principle failure is high
contact resistance caused by solder flux on the
contact surfaces. To avoid this, be sure to follow
good soldering practices. Use the proper solder
with the proper flux core, maintain the proper
soldering temperature, use the proper soldering
iron tip for the work, and never use liquid flux
when soldering a switch.
Do not use solvent baths or washes with any
unsealed electromechanical parts. Switches,
unless they have been especially protected
suffer badly. Solvents readily dissolve fluxes
and carry them into the contact area of switches.
A thin, hard flux coats the contact surface after
the solvent evaporates. Additionally, solvents
may dissolve and wash away lubricants in
switches. Lubricant loss may prevent proper
mechanical action.
Exercise similar precautions when you mount a
switch to a printed circuit board. Maintain proper
solder temperatures and follow proper cleaning
techniques. Avoid subjecting these switches to
lengthy solder baths. The excessive heat can
deform the plastics.
RFI/EMI SHIELDING
Some applications require shielding against
Radio Frequency Interference and/or Electro-
Magnetic Interference. Experts feel that the
most effective way to achieve shielding is to
provide a conductive bridge across the
component mounting hole. They also generally
agree that there is no good method for testing
shielding. So, the equipment manufacturers
themselves must identify and solve specific
problems. Component manufacturers can
generally assist in the solution of shielding
problems.
60525-5997 • USA • Phone: [phone] • Fax: [phone] • www.grayhill.com
RFI/EMI testing has recently been incorporated
into MIL-S-3786 for rotary switches.
Requirements are 1.0 ohm maximum dc
resistance between the mounting bushing and
operating shaft initially and 10.0 ohm maximum
dc resistance following environmental and
mechanical
manufacturers feel they are satisfying their
needs with a measurement of .025 to 10 ohms
for the expected life of the switch. Under most
circumstances, standard non-sealed switches
pass the larger value easily. The lower value
(.025 ohms) requires special attention and parts
for compliance over the life of the switch.
SWITCH SELECTION
Whenever possible, use standard switches and
contact configurations. Standards provide the
greatest economy and the best delivery. When
you need a deviation, it pays to consult with your
suppliers as soon as possible. At the early
stages of the design, there are many low cost
options for achieving the results. At the late
stages of design, some of the options may no
longer be open. For example, size may be
restricted. This might result in a more costly
redesign.
Typical standard rotary options are as follows:
coded contacts, homing rotor effect,
progressively shorting contacts, PC mountable
terminals, rotary switch spring return positions,
and push-to-turn or pull-to-turn mechanisms.
Limited panel space may be solved by a
concentric shaft rotary switch. It is two rotary
switches, located one behind the other. There
are other concentric shaft possibilities. A rotary
switch can be combined with another
component. These include a potentiometer, a
pushbutton switch, and a mechanical element.
The most cost effective design may be one of
these concentric options. But, selection must
be made at the outset of equipment design.
tests.
Many
equipment