| 摘要 |
<P>PROBLEM TO BE SOLVED: To simplify the structure by reducing the number of equipment and to smooth pressure change of a gas in a pulse tube. <P>SOLUTION: A valve control device for PWM (Pulse Width Modulation)-controlled three-level pulse tube refrigerator includes: series connected first compressor 1 and second compressor 2; a first buffer tank 11 and a second buffer tank 12 connected in parallel with them; series connected first electromagnetic valve V1 and second electromagnetic valve V2; series connected third electromagnetic valve V3 and fourth electromagnetic valve V4; the pulse tube 3 bridge-connected among the electromagnetic valves V1, V2, V3, V4; a fifth electromagnetic valve V5 connected among the pulse tube 3, the first buffer tank 11 and the second buffer tank 12; switching circuits 4-8 for controlling the electromagnetic valves V1, V2, V3, V4, V5, respectively; and a host electronic controller 9 that outputs a PWM signal for controlling them and distributes the PWM signal. <P>COPYRIGHT: (C)2012,JPO&INPIT |
