Yes, that should work. The siphon should stop when the water level in the overflow reaches the level of the T on the outside of the tank. When the water level in the overflow goes back above the T the siphon should start on its own. To make your picture a bit more accurate raise the water level in the overflow (from half way up the overflow) up to the level of the T. This would be the static level of the water inside the overflow. Any water in the overflow that is above this level will be pressure pushing the water through the piping.
I.E. - The distance from the T to the water level in the overflow will determine the amount of drop in the siphon... and the amount of water pressure in the siphon... hence the flow rate. In other words, the lower the T is outside the tank the greater the potential flow will be.