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A thyristor is a "triggered" device. It will remain off until its gate electrode is made to conduct. It will then stay on (showing a very low resistance) until the power is removed, or (in Gate Turn Off devices) until a turnoff voltage is applied.
A transistor can be used as a variable-resitance element. While it can be made to switch (like a thyristor) it does not need any special turn-off: just remove the input signal and it will go open circuit.
A transistor can be made to respond to a vaying input signal with a varying resistance, so it can be used as a linear (analogue) amplifier.
What else can I help you with?
What circumstances led to the invention of the transistor in 1947?
before the invention of transistor,thyristor was used instead of transistor but thyristor produces more heat in the circuit and size is more when compared to transistor
Why doesn't an SCR switch off once it turns on even after reducing gate potential?
A thyristor or silicon controlled rectifier (SCR), as they are sometimes known, consists of two transistors. A pulse on the gate turns on the second transistor which then turns on the first transistor in the combination. Turning on the first transistor enables anode current to flow and maintains a base current for the second transistor which keeps it on.See the Related link for an equivalent circuit for an SCR or thyristor.
What is the thyristor firing circuit?
The thyristor is basically used a switch in an AC circuit to control the amount of power fed to the load. To turn on this switch an "electric" pulse should be applied to the Gate terminal of the Thyristor. A circuit which supplies the "electric" pulse is called the firing circuit.
2 transistor analogy for scr and derivation for expression of anode current?
a thyristor can be considered as two complementary transistors , one pnp- transistor, and other npn transistor
What does forced commutation mean?
The term "Forced commutation" is used when a thyristor is turned off using external components. If a thyristor is used in a DC circuit, when first turned on, it will stay on until the current goes to zero. To turn off the thyristor it is possible to use a Forced commutation circuit. The circuit creates a reverse voltage over the thyristor (and a small reverse current) for a short time, but long enough to turn off the thyristor. A simple circuit consist of a precharged capacitor and a switch (e.g. another thyristor) parallel to the thyristor. When the switch is closed, the current is supplied by the capacitor for a short while. This cause a reversed voltage over the thyristor, and the thyristor is turned off.
Is BT169 a npn or pnp transistor?
BT169 is neither an NPN nor a PNP transistor. BT169 is a thyristor, otherwise known as a silicon controlled rectifier.
Why diode should be connected in anti-parallel with thyristor in inverter circuit?
A diode is connected in anti-parallel with a thyristor in an inverter circuit to provide a path for reverse current during the thyristor's off state. This configuration allows the diode to conduct when the voltage across the thyristor becomes negative, ensuring safe operation and preventing damage to the thyristor. Additionally, it helps in managing the switching characteristics and improves the overall reliability of the inverter circuit.
Why is it necessary to bias a transistor when it is to be used as an amplifier?
Biasing is necessary in a transistor circuit to keep the transistor working. Without proper biasing, the circuit will fail
What does a thyristor works as a circuit breaker?
A thyristor is a type of semi-conductor and is used in a circuit to control the application of electrical power to a load. They are often found as the switching element in light dimmers and can be used as control elements in power supplies (variable or regulated). Types of thyristors are diacs, triacs, sidacs and SCRs (silicon controlled rectifier).
What is a line commutation?
it is the natural commutation ...by making open circuit or short circuit on the thyristor to make it turn off.
What is thyristors?
A thyristor is a part of a alarm circuit you use it so the alarm stays on
What is transistor relay driver?
a transistor circuit for driving the coil of a magnetic relay.
