Andrew Leigh
Member
Hi
I found a BT138 (I'm sure there are better) to play around with. I don't know what I am looking at. It would appear as if the required gate voltage is between 0.7 and 1.5V max whilst the latching current is around 40mA.
If the gate current is to be limited to 40mA then I was hoping that the 330R with the LED would do this. The LED will hopefully illuminate when the Triac is conducting. Currently the 2N3906 is allowing a 12V signal to switch the relay. If the switching voltage for the BT138 is a max of 1.5V how will I reduce the voltage accordingly.
I have attached the original and working schematic with the modified schematic below, am I on the right track or am I going to kill myself?
Cheers
Andrew
I found a BT138 (I'm sure there are better) to play around with. I don't know what I am looking at. It would appear as if the required gate voltage is between 0.7 and 1.5V max whilst the latching current is around 40mA.
If the gate current is to be limited to 40mA then I was hoping that the 330R with the LED would do this. The LED will hopefully illuminate when the Triac is conducting. Currently the 2N3906 is allowing a 12V signal to switch the relay. If the switching voltage for the BT138 is a max of 1.5V how will I reduce the voltage accordingly.
I have attached the original and working schematic with the modified schematic below, am I on the right track or am I going to kill myself?
Cheers
Andrew