Phase angle controller question

Kolas, Sun Nov 20 2016, 04:12AM

Hi guys. I'm working on a phase angle controller...
The cost of triacs is prohibitively expensive for the amount of current that I am trying to control. Luckily, older high rating thyristors are available locally for 1/10th the price of new ones.
So instead, I have chosen the use of discrete thyristors.

My question is: Can I drive both gates with secondaries from a single GDT? Or will this cause an over voltage in either of the SCR's that is reverse biased when the gate pulse is applied to it?
To put my question another way; are the reverse blocking voltage ratings applicable when the Gate is being triggered?

It is certainly possible to apply pulse steering and use two different trigger circuits. However, this would result in twice the gate drive components necessary.

Any helpwould be greatly appreciated!
Re: Phase angle controller question
Sulaiman, Sun Nov 20 2016, 11:37AM

If each secondary has a series diode to the thyristor gate then one pulse transformer should be enough.