Systems methods and apparatuses for regulating the delivery of negative pressure therapy are described. The system includes a negative pressure source an energy source and a switch. The switch can include a first conductor electrically coupled to the negative pressure source a second conductor electrically coupled to the energy source and a diaphragm having a first position electrically coupling the first conductor to the second conductor and a second position separated from the first conductor and the second conductor. The diaphragm is configured to move between the first position and the second position in response to a differential between a control pressure and a therapy pressure.
