Patent ID: 7605495

Claim:
A circuit configured to provide two D.C. voltages of inverted polarities based on an A.C. voltage across a first A.C. terminal and a second A.C. terminal, comprising; two first diodes having respective anodes directly connected together in common and respective cathodes; two capacitors having respective first electrodes respectively connected to the first and second terminals of said A.C. voltage and having respective second electrodes respectively connected to the cathodes of the two first diodes; a controllable current source having a first terminal connected to the anodes of said first diodes; two second diodes having respective anodes connected respectively to said A.C. terminals and having respective cathodes directly connected together in common and connected to a second terminal of said controllable current source; a first control circuit configured to control said current source; and two third diodes having respective anodes directly connected together in common and respective cathodes connected to said A.C. terminals, respectively, said control circuit sampling a power supply between the cathodes of the second diodes and the anodes of the third diodes.