Method and apparatus for transformerless safety isolation in a power supply

• Main Authors: MATTHEWS DAVID M.H, BAURLE STEFAN, SAINT-PIERRE ROLAND S
• Format: Patent
• Language: English
• Published: 01.11.2007
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

An apparatus and method are disclosed to provide transformerless safety isolation in a power supply. One example regulated power converter includes input terminals included in a primary circuit of the power converter. Output terminals are included in a secondary circuit of the power converter. A plurality of safety capacitors including first and second safety capacitors are also included. Each of the plurality of safety capacitors includes a respective first terminal coupled to the primary circuit and a respective second terminal coupled to the secondary circuit. The plurality of safety capacitors galvanically isolates the primary circuit from the secondary circuit. A power switch is included in the primary circuit. The power switch is coupled such that switching of the power switch causes energy to transfer between the primary and secondary circuits through the plurality of safety capacitors. Substantially all of the energy that is transferred between the primary and secondary circuits is through the plurality of safety capacitors.