| 摘要 |
PROBLEM TO BE SOLVED: To provide a switch circuit that discharges electric charges stored at a high DC voltage at a high speed, reduces a saturation voltage lower and obtains an excellent characteristic in noise countermeasures. SOLUTION: The switch circuit consists of series connection of MOSFETs Q1-Q29 and configures a switch block SS1. A drive signal is applied to the MOSFET Q1 via an isolation transformer T1 to sequentially turn on the other series MOSFETs. Since number of the series connected MOSFETs is limited to 29, the saturation voltage of even the uppermost stage MOSFET 29 is kept within a practical range. Switch blocks SS1, SS2, SS3, SS4 each similarly configured are connected in series to obtain a withstanding voltage against a prescribed high voltage. A drive signal line 4 with a thick insulating coating is used for each primary winding of isolation transformers T1-T4. For mount of the switch block SS1 or the like, several MOSFETs are mounted on a printed circuit board and the printed circuit boards are connected in series via a mother board. |
