Hello!
I am working on a car power Converter to drive anything - even transformers. I will compare a triangle wave to a sine wave and drive a ferrite core with the resulting 100kHz
PWM Transformer. First question of all: Will it even change the voltage? Or will it always be 325V with just modified duty cycle, or will it change the output Voltage at all? And than... I want to add a Filter on the output - the problem is, that the filter effect depends on the resistance which is different at different power output levels.
How can I do that? And the more important thing: How do I even make the output voltage change over the PWM cycle? If this only works with a filter... then how do I make the filter work at very low power levels like 5W? For a 3 stage Filter I would need about 30mH, which actually is quite expensive, since I want to support 5A of current.
But realy... How Do I make the output voltage change by just having the PWM? That is my most concern.
Please help me to get this done. I cannot find ANY professional Car power converter. Just some cheap circuits, that drive a regular mains transformer with 50Hz square wave which obviusly won't ever work out as planned and is highly uneffective. That's, why I chose PWM. I got the circuit done with only discrete parts and one comparator.
What exactly determins the output voltage through a regular ferrite core switching transformer?