▁the ▁ 2 0 th ▁century , ▁a ▁variety ▁of ▁technology ▁was ▁developed ▁to ▁enh ance ▁the ▁program m ability ▁of ▁water ▁features ▁and ▁f ount ains . ▁One ▁such ▁development ▁is ▁the ▁sequ encing ▁device . ▁Se qu encing ▁devices ▁achieve ▁fast ▁and ▁smooth ▁water ▁sequ encing ▁effects ▁within ▁a ▁large ▁water ▁feature . ▁A ▁sol en oid ▁device ▁can ▁produce ▁sequ encing ▁effects ▁of ▁up ▁to ▁ 1 0 x ▁per ▁second ▁at ▁high ▁switching ▁spe eds ▁with ▁no ▁water ▁ham mer . ▁ ▁How ▁used ▁Over ▁the ▁past ▁number ▁of ▁years ▁f ount ain ▁design ers ▁have ▁been ▁experiment ing ▁with ▁interactive ▁water ▁features ▁ent icing ▁the ▁vie wer ▁in ▁to ▁particip ate . ▁ ▁F ount ains ▁that ▁entertain ▁and ▁are ▁ch ore ograph ed ▁with ▁music ▁and ▁color - ch anging ▁lights ▁have ▁become ▁more ▁popular . ▁ ▁Switch ing ▁devices ▁Dec or ative ▁f ount ain ▁systems ▁employ ▁fluid ▁ampl ifiers ▁to ▁generate ▁their ▁decor ative ▁displays ▁and ▁effects . ▁Fl uid ▁ampl ifiers ▁rely ▁on ▁a ▁fluid ▁control ▁stream ▁to ▁switch ▁a ▁fluid ▁power ▁stream . ▁Fl uid ▁ampl ifiers ▁are ▁so ▁named ▁because ▁a ▁low - energy ▁fluid ▁control ▁signal ▁can ▁control ▁and ▁switch ▁a ▁high - energy ▁fluid ▁power ▁stream ▁to ▁produce ▁an ▁output ▁signal ▁of ▁higher ▁energy ▁level ▁than ▁the ▁fluid ▁control ▁signal . ▁In ▁fluid ▁ampl ifiers , ▁a ▁fluid ▁power ▁stream , ▁after ▁leaving ▁a ▁no zz le , ▁is ▁switched ▁select ively ▁to ▁one ▁or ▁more ▁of ▁a ▁pl ur