An extended voltage range LED string driver comprising: an electronically controlled switch exhibiting a first port, a second port and a control port; a source of predetermined voltage connected to the control port of the electronically controlled switch; an LED string driver operatively connected to the first port of the electronically controlled switch; and a means for connecting an LED string to the second port of the electronically controlled switch; the electronically controlled switch being arranged to conduct between the first and the second port only when the voltage at the first port is within a predetermined range of said predetermined voltage.