Thyristor - current flows from gate to cathode?


Joined Mar 14, 2008
0.6V may not be enough to trigger the thyristor. There should be a resistor in series with the gate.

Post the circuit diagram.


Joined Feb 28, 2009
Also, you are aware that once it is triggered, since you are using DC, the only way to shut it off is to somehow reduce the current through it to a level below the minimum holding current. According to the data sheet, that is between 5 an d 8 ma.


Joined Mar 6, 2009
Hi mlkjhgfds,

You didn't mention the nature of the load that is being switched to the 30V DC rail. If you have been inadvertently shorting the 30V DC supply with the Thyristor it may well be damaged.

One could easily verfiy the integrity of the Thyristor by applying a constant DC voltage [say 1.5V via a 100Ω limiting resistor] to the gate-cathode circuit and checking whether load current flows in the non-pulsed gate drive condition.