I have a puck-style SCR with a cathode, anode and gate. I'm planning on using it to dump two series capacitors (450v + 450v) into a coil for a "coilgun" project. I understand that the SCR is triggered when a circuit is completed through the gate and anode using, for example, a battery and a simple switch. My SCR's datasheets specify IgtVgt (in mA/V) to be 300/3. I'm assuming that this means I need 300mA at 3 volts through the triggering circuit to turn the SCR on. My question is, do I need a resistor in the triggering circuit to protect it from the anode that is connected to the capacitor bank charged to 900v? Or, do I just need a resistor to get the 3 volts (probably a couple of AA batteries) to produce 300mA?