I was thinking about how to create a simple system to allow a range of voltages to charge a battery with high efficiency while being simple and economic.
i thought about using a pulse transformer for that but however with the voltages on the secondary somewhat smaller than the battery voltage
in that manner the primary must be allowed to collapse to let the secondary have the apropriated voltage to send current into the battery but as the voltage is smaller the current will be higher but basically the transformer will work in a flyback step down mode
will a high voltage switch at the primary side and proper protection it would be effective to charge a battery from some different voltage ranges and it would be efficient because most energy will be transfered to the load
when we have a consistent voltage at the generator is no big deal developing a transformer this same task but is bulky and heavy
let me do an example the generator is doing 90 v in a given moment and the step down ratio is 90 it would have 1 v at the output during pulse on but when the pulse colapses it can go 12 times higher with a 1200 v transistor so at the output would be 12v but with 10x more current
lets think about that
if get 90v 3.3 amps 300w at the output there should be 12v 300amps this is the peak force
the load will kind of clamp the voltage by a certain extent but if no power is dissipated at the load side the protection will suffer and must be capable of burning this 300w this means many tvs and power resistor in there

so it can power a wide range of battery voltages too
/