Ring-flash circuit

I have an old cheap ring-flash that I’ve had to rebuild because of some broken internal wiring.
The unit itself is a Pentax-dedicated Vivitar, but although it has a full set of hot-shoe contacts, the only “dedication” function is the “flash-ready” indicator in the camera’s viewfinder.
I was thinking it should be possible to add TTL metering (it currently just pops off a full length burst every time), and so I’d need to add a quench circuit to the high-voltage side.
Does anyone know anything about flashes - is this just a question of some sort of high voltage crowbar across the tube supply, or does it involve the trigger too?
I’m not worried about recovering the lost energy, because the unit will only be used off a bench supply in a studio.


Thanks, Westfw!

That’s a pretty good resource - I love the idea of using a second discharge tube to crowbar the first!