One of the most elusive little critters in the electronics business as far as data goes - ...............but one can sum it all up that this little critter boils down to being something of a boost converter (step-up converter) - aka a DC-to-DC power converter with an output voltage greater than its input voltage. It is a class of switched-mode power supply (SMPS) containing at least two semiconductors (a diode and a transistor) and at least one energy storage element, a capacitor, inductor, or the two in combination. Filters made of capacitors (sometimes in combination with inductors) are normally added to the output of the converter to reduce output voltage ripple. These little critters would typically be utilised in your common garden lamp aka solar flare.