Multi-channel two-stage controllable constant current source and illumination source

A multi-channel illumination apparatus having a plurality of channels comprising

• a power source stage providing a controllable regulated output voltage, said regulated output voltage being controllable by pulse width modulation at a first frequency, and,
• a channel driver stage comprising
• a switching circuit connected to said output of said power source,
• a plurality of transformers equal in number to the number of channels and having primary windings connected to receive equal currents from said switching circuit, said transformers having magnetizing inductances and turns ratios which are substantially equal,
• a plurality of constant current channel drivers equal in number to the number of channels, wherein said constant current channel drivers are operated at a second constant frequency and connected to a secondary winding of a respective one of said plurality of transformers, and
• at least one series-connected string of light-emitting diodes connected to each constant current channel driver of said plurality of constant current channel drivers.