voltage doubler
... that Heinrich Greinacher invented his voltage doubler circuit in 1913 because the 110 volt power supply in Zürich was insufficient for his newly invented ionometer which required 200 volts?
... that <a href="./Heinrich_Greinacher" id="mwFgM" rel="mw:WikiLink" title="Heinrich Greinacher">Heinrich Greinacher</a> invented his <b id="mwFgQ"><a href="./Voltage_doubler" id="mwFgU" rel="mw:WikiLink" title="Voltage doubler">voltage doubler</a></b> circuit in 1913 because the 110<span id="mwFgY" typeof="mw:Entity"> </span><a href="./Volt" id="mwFgc" rel="mw:WikiLink" title="Volt">volt</a> power supply in <a href="./Zürich" id="mwFgg" rel="mw:WikiLink" title="Zürich">Zürich</a> was insufficient for his newly invented <a href="./Ionometer" id="mwFgk" rel="mw:WikiLink" title="Ionometer">ionometer</a> which required 200<span id="mwFgo" typeof="mw:Entity"> </span>volts?