An Overview of Transistors
Transistor: A transistor is a solid-state device that joins three positive-type and negative-type semiconductors. All transistors generally have three pins: base, collector, and emitter. Transistor is a bi-polar device that is a transistor with two junctions namely BE and CE DE EE FE. In theory, we take a specified formula and incorporate this by using any type of meter in figuring out the mathematical solution.
What are Thyristors?
Thyristors: A thyristor is a four-layer semiconductor, also called a Shockley Diode, consisting of alternating P-type and N-type materials (PNPN). A thyristor usually includes three electrodes: an anode, a cathode, and a gate, also known as a control electrode.
(Short History: The four-layer diode (also called a Shockley diode) was invented by William Shockley while he was at Bell Labs. Shockley believed the four-layer diode would revolutionize telephone switching circuits because it could replace the mechanical switches used by the telephone equipment of the time. In the mid1950s, Shockley founded Shockley Semiconductor Labs with the intent of constructing silicon transistors but soon changed the emphasis of his company to the four-layer diode. It was difficult to manufacture with the technology of the time, and Shockley’s company never managed to turn a profit. The four-layer diode eventually evolved into the SCR, which is essentially a four-layer diode with an added control gate.)
What are the three States of a Thyristor?
Thyristors operate in one of the following three states, depending on the requirements and applications:
Forward conducting: The primary operating mode of a Thyristor. It is switched to conducting mode and stays put until the current drops below a specific level called the holding current (What is holding current? Once the 4-layer diode is, at the ON state, conducting mode, it will continue to conduct until the anode current is reduced below an specified level).
Forward blocking: The thyristor blocks current from flowing backward, despite applying voltage in the direction that would signal the diode to conduct.
Reverse blocking: Current attempts to flow backward. A diode blocks the current, and the thyristor is not activated.
Transistors vs. Thyristors
Transistors need to be activated by an electrical pulse to signal the device to conduct current. Their primary mode is a pending state in between On and Off.
Transistors also need to be constantly activated by their base signal to conduct current. Unlike transistors, thyristors are either off or on. A signal enters the
thyristor gate will activate the device, it remains open until a current reverse occurs or the voltage falls below a specific level.
What are the LCSC Categories of Transistors/Thyristors?
Pre-ordered transistors, MOSFETs, Digital Transistors, Intelligent Power Modules (IPM), Darlington Transistors, Bipolar (BJT), Thyristors (SCR)/Modules, IGBT Transistors / Modules, JFETs, Darlington Transistor Arrays