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Laser Trimming (Automated)
-a method for adjusting the value of thick film resistors
using a computer-controlled laser system. -signal modification that causes the output to be energized
and remain energized (maintain output). Latched output may
be immediate or delayed. Usually, the latch is released
by closing a circuit between the reset (RS/D) terminal and
ground. -small current flowing through or leaking from the output
device in the Off state due to semiconductor characteristics. -the maximum rate at which a fluid is permitted or determined
to leak through a seal. The type of fluid, the deferential
pressure across the seal, the direction of leakage, and
the location of the seal must be specified. -the straight line for which the sum of the squares of
the residuals (deviations) is minimized. This method is
used to calculate B.F.S.L. linearity. -a solid state light source that emits variable light,
or (in MICRO SWITCH modulated LED controls) invisible, infrared
radiation. -control operating mode in which the output is energized
when the light beam is not blocked (retro/thru scan), or
object is present (diffuse) the photosensor is illuminated. -the deviation of the sensor output curve from a specified
straight line. Linearity error is usually expressed as a
percent of full scale output. -see Terminal Base Linearity -output that is a continuous amplified version of its input.
That is, the output is a predetermined variation of its
input. -see Terminal Base Linearity. -units = Amps/milliamps (DC) or Amps RMS/milliamps RMS
(AC). The maximum amount of current that a proximity sensor
will switch through its load. Load current for a particular
device can be calculated by dividing the load voltage by
the load resistance. Attempting to switch a higher load
current than the sensor is rated for will result in sensor
failure. -the impedance presented to the output terminals of a sensor
by the associated external circuitry. -the modification of an input signal that produces delayed,
pulsed, latched. or other output response. Logic circuitry
is sometimes an integral part of the control, but more often,
a separate plug-in card or module. -warehouse locations, light industry applications, material
handling operations. -a qualitative term having no exact definition. It usually
refers to a circuit having such low voltage and current
that there are no significant thermal effects at the contact
interface. Magnetic Blow-Out
Switch -contains a small permanent magnet which
provides a means of switching high DC loads. The magnet
deflects arc to quench it. -designed for applications requiring sustained contact
after plunger has been released, but with provision for
resetting. -the maximum variation from standard allowed by the manufacturer
between products with the same catalog listing. -to close or establish an electrical circuit. -the maximum value of supply voltage or current that can
be applied to the sensor at room conditions without causing
damage or performance degradation beyond specified tolerances. -the maximum amount of current that can flow through a
sensor and not cause sensor failure. -a physical quantity, property or condition which is measured
(e.g., pressure, acceleration). -life of a switch with no (or a negligible) electrical
load, and a specified combination of actuation, environment
and criterion of failure. Mechanical life usually is limited
by the life of the switch's flexing parts and bearing surfaces. -ability to operate with a specified media carrying pressure
(e.g., salt water). -the metal pattern deposited on the sensor chip (usually
outside the diaphragm area) to permit electrical connections
to be made to the chip. Aluminum is usually used, but has
potential contamination problems (known as the "purple plague"),
if not protected. MICRO SWITCH uses gold, which is impervious
to almost everything. -a net transfer of material from one contact to the mating
contact as a result of switching an electrical load. It
usually takes the form of a needle, cone or mound or one
contact face and a corresponding pit in the surface of the
mating contact. -this is an exact term only when applied to a specific
group of tested switches. It then means the lowest life
figure obtained from the test of that group of switches. -milling operations, areas of high humidity, stream.
-a photoelectric control that operates on modulated (pulsed)
infrared radiation, and responds only to that frequency
rather than steady light intensity. Modulated LED controls
offer a high rejection of troublesome ambient light. -output circuit protection designed to protect the output
device from damage due to a temporary (1-3 sec.) short circuit
or until an external fuse can interrupt current. -a switch with contacts that return from operated condition
to normal condition when actuating force is removed. Unless
otherwise stated, all switches in this catalog are momentary.
-a switch with contacts that return from operated condition
to normal condition when actuating force is removed. Unless
otherwise stated, all switches in this catalog are momentary. NEMA Ratings -National
Electrical Manufacturers Association ratings of an enclosure's
ability to provide a degree of protection against contact
with equipment and against specified environmental conditions. -noise results from the presence of undesirable electrical
voltages or current. It causes devices to operate erratically
(if the noise is on the supply line to a device), or produces
false information on erratic operation if present on wires
carrying signals from the output of a device to the load.
Noise can be present in the supply or picked up on lines
in many ways. Pick-up from noisy adjacent wires or metal
parts is possible. Good wiring practice and/or additional
parts can be used to diminish the effects of noise. -an approximate dimension value measured from the face
of the sensor to the nearest point of the target. It does
not take into consideration manufacturer's tolerance or
operational variables. Also known as the operating point. -a slang expression referring to a defective condition
in which a supposedly closed switch lacks electrical continuity. -inability under normal operation to ignite a hazardous
mixture. -controls designed for indoor applications subject to neither
bright ambient light nor extreme vibration. Usually incandescent
lamp controls, scanners and light source-photoreceiver pairs.
-the normal contact position of a switch exits when no
force is applied to the plunger. -the state of a control in which the output is high (logic1)
in voltage in the rest (Off) condition. -the state of a control in which the output is low (logic
0) in voltage in the rest (Off) condition. -process of creating sensor interchangeability. -a transistor consisting of two N-type regions separated
by a P-type region. -the condition when the pressure on each side of the sensing
diaphragm is equal. -the electrical output present, when the pressure sensor
is at null. -the change in null output value due to a change in temperature. Off Delay Logic -adjustable
delay (after input signal stops) before output is de-energized. -the supply or bias current flowing into a solid state
device when it is in the unactuated state (see Leakage Current). -the unit of electrical resistance. Resistance through
which a current of one ampere will flow when a voltage of
one volt is applied. -adjustable delay (after onset of input signal) before
output is energized. -see pulsed logic . -the characteristic of an object that prevents light from
passing through. The opposite of translucent. Opaque objects
are easy to detect since they block light almost entirely. -the position to which the contacts move when the plunger
is traveled to the operating point or into the overtravel
range. -the commonly specified force, torque and linear or angular
travel properties of a switch. Examples: operating or release
force, operating point, differential, overtravel. -the force which must be applied to the plunger to cause
the moving contact to snap from the normal contact position
to the operated contact position. -refers to the condition of the photosensor (dark or light
illuminated) that energizes output. A mode selector switch
determines the operating mode. -that position of the plunger at which the contacts snap
from the normal contact position to the operated contact
position. -actual range over which sensors can be operated. Usage
outside the temperature limits will result in loss of stability,
change in operate point and possible permanent damage to
the sensor. Nominal sensing distance is determined at 25
- C. -power or intensity of the projected light available from
a particular emitter; beam intensity. -an output is produced when any one or more inputs are
present. -the useful energy delivered by a circuit or device. Can
mean energy produced at the output terminals of an amplifier-a
source of energy. -the impedance across the output terminals of a sensor
presented by the sensor to the associated external circuitry.
-the rms, peak-to-peak (as specified) AC component of a
sensors DC output in the absence of a change in input pressure. -the maximum specified pressure which may be applied to
the sensing element of a sensor without causing a permanent
change in the output characteristics. -as an operating characteristic of a switch, overtravel
is the distance through which the plunger moves when traveled
from the operating point to the full overtravel point. As
a characteristic of the actuation applied to the switch,
overtravel is the distance the plunger is driven past the
operating point. Parallel Circuit -a
circuit in which current has two or more paths to follow.
Two electrical elements are in parallel if both terminals
of both elements are electrically connected. -a resistive, bulk effect type of photosensor, the type
used when it is desirable to wire several photoreceivers
in series or in parallel. The resistance decreases with
increasing light intensity. -a unit consisting of photosensor, focusing lens, and protective
enclosure. -a light sensitive portion of a photoelectric control that
converts a light signal into an electrical signal. MICRO
SWITCH uses photocells and phototransistors. -a type of photosensor. Typically used where speed of response
is important or ambient temperature variations are great. -a change in resistance in a semiconductor, caused by an
applied stress to the diaphragm. -controls that emit a visible LED beam and use a special
lens which filters the beam of light so that it is projected
in one plane only. The control responds only to the de-polarized
reflected light from corner-cube type reflectors (FE-RR1)
or special polarized reflective tape. -a diode consisting of one N-type region and one P-type
region. -the number of completely separate circuits that can pass
through a switch at one time. A single pole switch can control
only one circuit at a time. A double pole switch can control
two independent circuits (such as a 120 volt AC heater and
a 6 volt DC lamp) at the same time. The number of poles
is completely independent of the number of throws and number
of breaks. -compounds having long-chain molecular structure, formed
from simple organic contaminants on contacts, under the
influence of contact wipe and the catalytic effect of the
contact material. -units = Watts/milliwatts (DC) or Volt-Amps (AC). The amount
of power that is consumed and converted to heat in normal
operation. Supply Voltage (max) x Supply Current -an electromechanical switch having predetermined and accurately
controlled characteristics and having a spring loaded quick
make and break contact action. -force applied to, or distributed over a surface expressed
in terms of force to area ratio. -pressure measured relative to absolute zero pressure (perfect
vacuum). The output of the absolute sensor will change as
a result of barometric pressure change. Thus it can be used
as a barometer. -pressure between two points of measurement. -pressure measured relative to ambient pressure. The output
of a gage pressure sensor, contrasted to an absolute pressure
sensor, does not change with a change of barometric pressure. -the pressure limits over which the pressure sensor is
calibrated or specified. -the pressure relative to which a differential sensor measures
pressure. Ambient pressure is a specific case of reference
pressure. -a device that converts an input pressure into an electrical
output. -the average pressure on the inputs of a differential pressure
sensor (sometimes referred to as common mode or working
pressure). -the distance through which the plunger moves when traveled
from the free position to the operating point. -see Overpressure. -a sensor with the ability to detect the presence of a
metal target, within a specified range, and without making
physical contact. -a resistor connected across the output of a device or
circuit to hold the output equal to or less than the zero
input level. Also used to lower output impedance of digital
or analog devices. Usually connected to a negative voltage
or ground. -a resistor connected across the output of a device or
circuit to hold the output voltage equal to or greater than
the input transition level of a digital device. Usually
connected to the positive voltage or plus supply. -a momentary sharp change in current, voltage, or other
quantity that is normally constant. A pulse is characterized
by a rise and fall and has a finite duration. -a signal modification that produces output independently of input signal duration. Pulse duration (dwell) is usually adjustable. Also referred to as one-shot logic. Pulsed logic may be immediate or delayed. |
