This
category consists of a variety of products that can be used in
non-contact sensing situations. Products types consist of IR
(InfraRed) LED (Light Emitting Diode), VCSEL (Vertical Cavity
Surface Emitting Laser), photodiodes, phototransistors, photodarlington
and photologic® components.
- Infrared
LED’s emit a wide range of wavelengths with intensities
reducing from the center wavelength. LED components have
half power points from 15 degrees to 130 degrees inclusive
(total degrees between half power points). Power measurements
for LED’s are generally in mW (milli-Watts), mW/cm2
(milli-Watts per centimeter squared) or mW/Sr (milli-Watts
per Stradian). LED’s can be used in a wide variety
of sensing and illumination applications. Most IRLED’s
are used strictly for sensing applications.
- VCSEL’s are a new type of Light Emitting Device that generates
a significantly greater amount of optical light (power
in milli-Watts,
mW) than the LED, requiring a much lower drive current,
radiating in a vary narrow wavelength and having vary
narrow half power
points.
- Photodiodes (optical diodes that turn on when of light strikes an active
surface) are the fastest of the Optoelectronic sensors. The
photodiode requires special circuitry to connect, but is
suited to the widest range of applications.
- Phototransistors (optical input transistors utilizing light striking the base
of the device to operate) provide the next higher level of
components reducing the requirements for special gain circuitry
required by a photodiode. Phototransistors have slower rise
and fall times than a photodiode.
- Photodarlington (Optical input transistor pair utilizing light striking the
base of the device to operate) provide a higher gain than
a phototransistor for those applications where high gain
is important. Photodarlington devices have slower rise and
fall times than a phototransistor.
- Photologic® devices (optical input integrated circuit utilizing light
striking the base of the device to provide ECL and TTL outputs)
are the easiest to use. They provide an output that switches
at a specific light level. These devices have hysteresis
in the input light level to stabilize the output state of
the device. The logical families consist of Totem-Pole, pull-up
resistors and open collector outputs with standard and inverted
output states. These devices require the least amount of
external circuitry thus making them very easy to use in many
applications.
- IRLED’s
photodiodes, phototransistors, photodarlingtons and
photologic® components
can be purchased in a variety of package configurations
such as endlookers, lensed endlookers, sidelookers,
lensed sidelookers, laterals, lensed laterals, T-1, lensed
T-1,
T-1 ¾ lensed T-1 ¾, TO-46, Plastic TO-46,
Metal Can TO-46, TO-18, Plastic TO-18, Metal Can TO-18,
Surface
Mount, and other specialty packages.
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