Power supply for an electrostatic spray gun

摘要

An improved power supply (5) for an electrostatic spray gun having a voltage multiplier circuit (12) adjusts to variations in the output load conditions of the multiplier circuit (12) and dynamically modifies the operational loadline of the multiplier circuit (12) in order to maintain optimal operating conditions for the spray gun notwithstanding output load variations. The power supply (5) utilizes a loadline manipulation circuit (16) coupled to a feedback circuit (14) that monitors the output load, and the manipulation circuit (16), in response to a feedback signal from the feedback circuit (14) that is proportional to the output load, varies the input voltage level to the multiplier circuit (12) to modify the loadline of the power supply (5) in response to varying load conditions. The manipulator means (16) of the power supply (5) has memory means (29) to store a variety of external commands which will control the manipulation means (16) and a user interface (25) to enter the external commands into the memory (29). The power supply (5) also comprises a voltage limiting circuit (60) coupled to the output of the multiplier circuit (12) which regulates the output voltage level of the multiplier circuit (12) so that when the output load current increases above a predetermined maximum level the output voltage is reduced to reduce the high voltage stress on the multiplier circuit (12) and high voltage circuitry and reduce the amount of insulation that must surround the multiplier circuit (12) and high voltage circuitry of the power supply (5) in order to insulate it from ground potential.