( ( This energy ) ( ( is ( used ( to ( charge ( the ( high-voltage capacitor ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT This) (NN energy)) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB charge) (NP (DT the) (JJ high-voltage) (NN capacitor))))))) (. .)))
This energy is used to charge the high-voltage capacitor.
(ROOT (S (NP (NNP Voltage)) (VP (VP (VBZ is) (RB not) (NP (NP (DT the) (JJ same)) (PP (IN as) (NP (NN energy))))) (, ,) (CC but) (VP (VBZ means) (NP (NP (DT the) (NN energy)) (PP (IN per) (NP (NN unit) (NN charge)))))) (. .)))