Why are we using GTO instead of SCR ?

[Alwaleed2]

advantage of gto vs scr

what is the problem in the turnning the SCR off by inverting Voltage across the gate and the cathod ?

why using the GTO (GCS) instead of SCR to avoid this problem ??

I need more explaination pleas

 

[leomecma]

Re: Why GTO instead of SCR ?

Once SCR begins to conduct, it is latched on and it cannot be turn off by the gate, only when reversing polarized. GTO can turned off aplying a negative gate-cathode voltage.

There are three significant differences between a GTO and a SCR. First the gate and cathode structures are highly interdigitated, with various types of geometric forms being used to lay out the gates and cathodes, including complicated involute structures. The basic goal is to maximize the periphery of the cathode and minimize the distance form the gate to the center of cathode region.
Second, the cathode areas are usually formed by etching away the silicon surrounding the cathodes so that they as islands or mesas. When the GTO is packaged, the cathode islands are directly contacted toa a metal heat sink, which also forms the cathode connection to outside world.
A third major difference is noted in the anode region of GTO. At regular intervals, n+ regions penetrate the p-type anode (p1 layer) to make contact with the n- region taht forms the n1 base layer. The n+ regions are overlaid with the same metallization thatcontacts the p-type anode resulting in a so-called anode short. The anode - short structure is used to speed up the turn-off of GTO.

 

[zhi_yi]

Re: Why GTO instead of SCR ?

what is the GTO and GCS :?:

 

[leomecma]

Re: Why GTO instead of SCR ?

They are same thing > gate-controlled switch (GCS) or gate turn-off thyristor (GTO)