Misc Thyristors and Opto Dev

Phototransistor - a light-sensitive junction that amplifies the base current as the illumination increases

Radiance - emission of electromagnetic wave from a surface

LASCR - A silicon-controlled rectifier operates essentially as

Photovoltaic - Materials that produce a voltage when struck by light

Darlington Transistor Coupler - Optocoupler type used for increased current capability

Photon - A quantum of visible light

Photodetector - Optoelectronic device that detects and conducts light detection

Photo-Darlington transistor - phototransistor fabricated as Darlington amplifier

Phototriac output coupler - optoisolator needed for isolated triac triggering

LED - Photo-source device consisting of PN junction

Optoisolator - Optoelectronic device that allows interfacing circuits

Photosensitive - Materials that respond to radiant energy, especially light

Solar cell - Photovoltaic component that produces 0.25

Photo FET - A photodetector with the advantage of high input impedance

reverse - photodiodes are normally operated at the _ region

angstrom - unit of length, measure of displacement equal to 0.0000000001 meter (10 -10 m)

DC current transfer ratio - This parameter is the ratio of the output current to the input current through the LED

Photoemissive - Materials that emit electrons when struck by light

Photoresistor - Semiconductors with large minority

Photosource - Optoelectronic device that performs light emission

Dark current - Reverse photodiode current

Optocoupler - Optoelectronic device that allows interfacing circuits

Luminous energy - Emitted energy in the form of photons

Photoconductive - Materials whose electrical resistance varies inversely

forward - An LED operates in _ bias

SBS - Can be triggered into conduction by exceeding the breakover voltage in either direction or by a positive or negative pulse applied to the gate

GCS - positive pulse to the gate triggers it into conduction while a negative pulse to the gate turns it off

GCS - Called a turnoff thyristor, and is similar to an SCR

Shockley - Reverse blocking diode thyristor

SBS - Operates like a SUS, but will conduct in either direction

SBS - V-1 characteristic curve is similar to that of the DIAC, but it has more pronounced "negative resistance" region

SCS - Operates like an SCR, but triggered on by either gate lead

SBS - Have breakover voltages lower than those for DIACs 8 v being the most popular rating

SUS - Can be triggered by normal breakover voltage or a positive or negative pulse applied to the gate

False - Radiant energy pertains to the time rate of flow of radiant energy, in ergs or watts per second

True - The first visible red LEDs were produced using gallium arsenide phosphide (GaAsP) on a gaAs substrate

True - Light frequency band ranges from 400,000 750,000 GHz

True - A photometer is used for measuring the intensity of light source

True - Reverse breakdown for a LED is much less than for a silicon rectifier diode

False - In a photoresistor, the minimum resistance when there is no light is termed as light resistance

True - Photometric system is the measurement of spectral emission characteristics of sources of visible light

True - The introduction of gallium nitride made way for the production of blue LEDs

 True - a digital output coupler consists of a high-speed detector circuit followed by a transistor buffer stage

True - In a photoresistor, the maximum resistance when there is no light is termed as dark resistance

False - In a photoresistor, when there is incident light, there is only a small thermally generated collector-to-emitter leakage current, called light current

False - Light emission occurs in semiconductor material when photons strike the material and release valence electrons

True - Isolation voltage is the maximum voltage that can exist between the input and output terminals without dielectric breakdown occurring

True - When light strikes the photoresistor, electron-hole carriers are released, hence, the resistance decreases

 False - A LASCR output coupler converts an input current variation to an output current variation

False - optoelectronic device data transfer

True - electromagnetic radiation at wavelength somewhat shorter than those of visible light reverse to the ultraviolet band