| 摘要 |
PROBLEM TO BE SOLVED: To reduce radiation noise by forming a first region of a high conductivity in the proximity of a printed board and forming a second region of a lower conductivity than the first one away from the printed board, in a power supply equipment provided with the main body of an equipment mounted with a rectifier and a high frequency power circuit. SOLUTION: Between an AC input terminal of a full-wave rectifier DB and the main body A of an equipment, capacitors C5 , C6 , C7 which have low impedance against high frequency waves are connected. High frequency current is allowed to flow in a coil 1 for supplying high frequency power from a high frequency power supply RP to generate high frequency electric and magnetic fields and thereby generate visible light by high frequency plasma current in an electrodeless discharge lamp LA. A sheet CS of a higher conductivity than the main body A is fixed in the proximity of a printed board 3. An electric and a magnetic field around the main body A are the vector sums of an electric and a magnetic field due to high frequency current in the direction shown by the arrow Y and an electric and a magnetic field due to high frequency current in the direction shown by the arrow Z, respectively, and therefore are canceled because of the sums of vectors in opposite directions and thereby radiation noise can be reduced. |
