I hope I understand your question. If you are using a Z1, you have two options to power a top light. One is the light is self powered(Uses a battery that mounts to the light) or a light that requires a external battery to power it. Saying that, it depends on light. The new LED's can be powered with a battery or a power tap as you called it Other lights only can be powered by a battery, built in or external battery. Most common light used in the field is a AB or Frezzi light. Both lights require external battery or a camera that has a AB tap.