Systems and methods for driving negative pressure sources in negative pressure therapy systems

An apparatus for applying negative pressure to a wound, the apparatus comprising:

• a source of negative pressure configured to provide negative pressure via a fluid flow path to a wound dressing placed over a wound of a patient, the source of negative pressure comprising an actuator configured to convert an electrical energy to a mechanical energy;
• a coupling circuit including an inductive reactance;
• a driving circuit configured to supply a driving signal to the actuator via the coupling circuit to cause the source of negative pressure to provide negative pressure;
• and
• a controller configured to control the driving signal supplied by the driving circuit,
• wherein the coupling circuit comprises an inductor electrically coupled in series between a first output of the driving circuit and a first input of the actuator and an electrical short electrically coupled in series between a second output of the driving circuit and a second input of the actuator.