Tag Archives: Electronic Components

UJT-Uni Junction Transistors

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Unijunction transistor (abbreviated as UJT), also called the double-base diode is a 2-layer, 3-terminal solid-state (silicon) switching device. The device has-a unique characteristic that when it is triggered, its emitter current increases re generatively (due to negative resistance characteristic) until it is restricted by emitter power supply. The low cost… Read more »

Silicon Unilateral Switch

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The diac and the silicon bilateral switch are grouped as bilateral or bidirectional devices because they can breakover in either direction. There are also breakover devices which breakover in only one direction; they fall in the category of unilateral or unidirectional breakover devices. Although unilateral breakover devices are more frequently… Read more »

Silicon Bilateral Switch

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Silicon Bilateral Switch Silicon bilateral switch (SBS) is another breakover device which is capable of triggering triacs, and it is popular in low-voltage trigger control circuits. They have breakover voltages lower than those for diacs, ± 8 V being the most popular rating. V-I characteristic curve of an SBS is… Read more »

Shockley Diode

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The four-layer diode, also called the Shockley diode after its inventor William Shockley, is essentially a low-current SCR without a gate. It is classified as a diode because it has only two external terminals through anode and cathode. Because of its four doped regions it is often called a P-N-P-N… Read more »

Photoconductive cells

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The photoconductive cell is a two terminal semiconductor device whose terminal resistancewill vary (linearly) with the intensity of the incident light. For obvious reasons, it is frequently called a photoresistive device. The photoconductive materials most frequently used include cadmium sulphide (CdS) and cadmium selenide (CdSe). Both materials respond rather slowly… Read more »

JFET-Junction Field Effect Transistor

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As already mentioned, JFETs are of two types viz N-channel JFETs and P-channel JFETs.Generally N-channel JFETs are preferred. N-channel and P-channel JFETs are shown in figures.   JFET-junction-field-effect-transistor Basic Construction. Its structure is quite simple. In an N-channel JFET an N-type silicon bar, referred to as the channel, has two… Read more »