This bloke is aproaching the problem in a much more systematic way than any back yard inventor I have seen.
He is using electronics & is working with a firm called PWM [Pulse Width Modulation] to control the gas production.

He is using proper scientific approach & is publishing his results, good or bad, on u-tube for peer review. He is no dummy & he has a nice little workshop equiped with all sorts of electric & electronic test equipment.
He approaches each problem with an open mind & learns fron setbacks & failures.

Well worth a look when you have nothing else to do.