To refine that a little bit, you need an H-bridge for each tram that is running. So for example, you could have 2 bridges (throttles), and multiple blocks. You could have 6 trams, but 4 of them parked on dead blocks, 2 each connected to one throttle (H bridge).
Again, you don't have to look far for the wiring, as it was common between about 1960 and 1990 on almost all layouts - before DCC came along.