當450V額定電容充滿電以後 若放電 放電電壓是不是450V?

你加入多大的電壓，就給充多少的電，放出的電壓也是這麼多，不過是電壓逐漸減小直到放完電。標明的額定450V是最大能承受電壓值，超過這個值電容將損壞。

According to the characteristic curve of capacitor discharging, it takes infinite time for a capacitor to discharge to zero volts. But as a normal practice, the amount of voltage it is charged to, is equal to the discharge.