This might seem somewhat basic but I am a little confused. I have been told that the terminals of a triac MT1 and MT2 can be used interchangebly. However , I was developing a lamp dimmer circuit today using a BT 139 - and this does not seem to be the case. The dimmer works only in a specific way. Any comments ?
It works either way, but it can be turned on only between gate and one of it's anodes, so you need to keep Gate to Anode voltage and change current direction and it will work.
Yes, but with different gate triggering sensitivity. For example the gate current can be 5mA and 13mA for a typical TRIAC in the above cases. Your circuit may not be able to provide the required gate triggering current.
Yes, but with different sensitivity. For example the gate current can be 5mA and 13mA for a typical TRIAC in the above cases. Your circuit may not be able to provide the required gate triggering current.
Like transistors if you go an stick a cuple of them in your multimeter each one will have difrent gain.Probobly this hapends here too (Since these things are made up of transistors)
Because the physical gate location is not symmetrical in the structure of the TRIAC construction. It is closer to MT1 so less current is needed to trigger the conduction of the TRIAC than the other cases.