someone could explain me the way a IGBT and a TRIAC works??
I assume that the Gate (in the IGBT and TRIAC) can be compared to a tap, right?? If this "tap" is controled,it allows more or less the current to pass from the colector to the emitter?
Please if some one could explain me that i'd realy be grateful.
Thank you all

 

er no.
Triacs and IGBT are Hard-ON and Hard-OFF (although there is a controllerble linear region for an IGBT).
You can think of a BJT as a tap (and also a MOSFET as a tap)

A TRIAC is back-to-back thyristors (thus bidirectional current flow) and can only be controlled turn-ON, they need their current flow to be zero for it to switch-OFF.

IGBT's are a power controlled switch that can be understood as a high-power PNP transistor on the output and a fast N-type MOSFET on the contol-input.
IGBT's are easy to switch since they have a MOSFET front-end.

 

Is a thyristor in any way like an SCR?

 

They are exactly the same device, just different names.

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I thought that SCR's, TRIAC's etc.. were in a class called "thyristors" is this right? If you ask to buy a thyristor, the vendor would respond "what do you want? SCR?

 

I dont know abt teh states but in the UK a thyristor is a thyristor and a triac is a triac. We dont tend to use the term "Silicon Controlled Rectifier" or SCR. However, it can be argued that most forms of power switches can control rectification. hence why not use SCR to group all types???

IGBT's in an active front-End to rectification. GTO's for a more controlled rectification scheme. Hence why I dont like the term SCR

 

As I mentioned before, an SCR and thyristor are exactly the same - just different names for the same device. A triac is different, it's essentially two thyristors back to back, so you can control full wave AC rather than just half wave.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk