How does Tap a Draft Work?

Does it continually inject Co2 into the jug?  Yes, it does become more carbonated.  I was hoping it reached a point and quit injecting Co2 into my beer.

I like British style ales with low carbonation.

How do I achieve this with this system?

Can you disconnect the CO2 until the beer gets a little flat, then give it another shot of CO2 for dispense?