The smaller white box next to the HV Power Supply is a variable low voltage DC power supply and is used to actuate the solenoid on the vacuum relay (discharge switch).是什么意思_The smaller white box next to the HV Power Supply is a variable low voltage DC power supply and is used to actuate the solenoid on the vacuum relay (discharge switch).在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句