( These ( ( ( ( use ( no power ) ) , ) ( relying ( on ( coils ( ( moving ( in ( a ( magnetic field ) ) ) ) ( to ( produce ( a signal ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT These)) (VP (VBP use) (NP (DT no) (NN power)) (, ,) (S (VP (VBG relying) (PP (IN on) (NP (NP (NNS coils)) (VP (VBG moving) (PP (IN in) (NP (DT a) (JJ magnetic) (NN field))) (S (VP (TO to) (VP (VB produce) (NP (DT a) (NN signal))))))))))) (. .)))
These use no power, relying on coils moving in a magnetic field to produce a signal.
(ROOT (S (NP (NNP Alternative) (JJ current)) (VP (VBZ is) (VP (VBN produced) (SBAR (WHADVP (WRB when)) (S (NP (DT a) (NN magnet) (CC or) (NN coil)) (VP (VBZ moves) (ADVP (RB back) (CC and) (RB forth)) (ADVP (RB repeatedly))))))) (. .)))