Thyristor - current flows from gate to cathode?

Discussion in 'General Electronics Chat' started by mlkjhgfds, May 24, 2012.

  1. mlkjhgfds

    Thread Starter New Member

    May 24, 2012

    I'm trying to switch 30V DC (anode) using a 0.6V, 40khz rectangular signal (gate) with this thyristor :

    The only thing coming out of the cathode is the gate signal regardless of what's on the anode. (yes I'm sure I wired the proper pins)

    My question is, did I burn the thyristor ? Is that what typically happens when it gets damaged ?

  2. crutschow


    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.
  3. BillB3857

    AAC Fanatic!

    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.
  4. t_n_k

    AAC Fanatic!

    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.