Difference between GTO and SCR

Hello, readers welcome to new post. We will discuss Difference between GTO and SCR. There is the use of a gate signal for GTO to get off while SCR is not off through the gate signal. For off the SCR, there is the use of a communication circuit but the thyristor can get off through a signal at a gate terminal.

Not use of distinct communication circuitry for GTO makes it effective for different applications than the SCR. Here we cover different points to find the basic differences. So let get started

Table of Contents

What is GTO

The gate turn-off thyristor is a semiconductor component that gets on and off through the gate signal.
It has a PNPN configuration that gets on through the application of a positive current from the gate and off through a negative signal from the gate.

A normal thyristor or conventional thyristor is used as an ideal switch for power electronic circuits. for on this thyristor, there is gate signal is provided but for off the device, there is the use of a communication circuit that enhances the prices of circuits and makes it heavyweight.
To overcome these features GTO was introduced. For GTO there is no use of a communication circuit but a gate signal is used.
For on GTO positive gate signal was used and for off negative gate signal was used. These features make it effective over the conventional thyristor
GTO is three pins PNPN structure device its pins are anode-cathode and gate.
It has four layers of PNPN and the anode is P layer having N defused on it

What is SCR

SCR is a solid state instrument used for power control of dc and ac circuits. Its name is SCR since consists of SCR and its operation is like the rectifier.
It is a very older part of thyristor groups. It comes with similar features to a thyristor tube.its structure is like the transistor
Its name first three letters are derived from THYRatron and the other 4 are transistors
It has 3 PN junctions with 2 stable states on and off. Its pins are anode-cathode and gate
Its structure has 4 layers of P and N in alternate fashion creating 3 PN junctions. Its Pn junctions are denoted as J1 J2 and J3
The use of threaded stud for SCR helps to place on the heat sink

The use of heat since is necessary since its rating is about ten KV and three thousand ampers current that resultant to power handling capacity of about thirty Megawatt
Its gate is closely configured to cathode pin

SCR vs. GTO

GTO is a 4 layer, 3 pin PNPN configured device, and its anode is defused in the P SCR. It also has 4 layers with a 3 pin PNPN configuration, but its anode is in the P layer.
There is no need for a communication circuit for GTO, so it is used for one-kilohertz frequency applications, while SCR uses communication circuits.
GTO has the same VI features as SCR, with a larger latching current value, and SCR has less latching current.
GTO has less voltage-blocking capability than SCR.
Turn of time of SCR is the reverse recovery time and gate recovery time, and GTO has storage fall time and tall time.
The gate triggering current for SCR is less than GTO.
GTO has high efficiency since it has fewer losses due to the communication circuit.

Why is GTO preferred over SCR?

The main benefit of GTO is that it can be off through the use of a negative gate signal having a certain amplitude value. It also does not use high communication circuits as used for off the SCR. GTO also has a higher switching speed than SCR, so it is preferred.

What are the 3 states of SCR?

The mode of operation SCR is based on biasing

Forward blocking mode (off state)
Forward conduction mode (on the state)
Reverse blocking mode (off-state)

Is SCR DC or AC?

A SCR is a DC or unidirectional device that conducts current in a single direction and works as a DC switch.

Why is SCR called a diode?

SCR is also called SCR diode, 4-layer diode, or thyristor. It is created through silicon that regulates high power and transforms AC into DC. In simple words, it is a rectifier.

What is the principle of SCR?

Its working principle is that when biasing voltage is provided to the gate terminal, it starts conduction. Since it is a unidirectional component, it converts current flow in a single direction.

How many types of SCR are there?

It has three types that are planar, mesa, and press pack type.

What is the advantage of GTO over SCR?

The basic benefit of GTo as compared to SCR is that it gets on or off by providing a pulse to the gate. The features of GTO for turning on with a gate signal and turning off with a gate signal of negative polarity provide features of thyristor

Why is GTO preferred over ordinary thyristor?

GTO comes with high efficiency also when gate-operated power loss and on-state losses are higher as compared to SCR. It is due to factors that gate causes losses and ON state loss for GTo is less than forced commutation losses of conventional thyristor.