 # PWM output control for flyback converter ( connecting both buck boost & flyback)

Hello everyone, I am so sorry to tell you that I am a total beginner in arduino programming and even basic programmings =( =(. However, I am just thinking about ideas for the burn in test of buck- boost converter. And It is told that the arduino UNO can be used to control the duty cycle of PWM ( and produce PWM in itself) . As a result, I 've come across these problems.

As the burn-in test is required for the buck boost converter to test its quality, much power loss is resulted as they are connected with resistors. However, I am just thinking about using an active load ( flyback) instead of passive load (resistor) for burn in test, with an aim to ' flyback' the power from the output of buck- boost converter being tested to the input of buck- boost converter through Flyback converter.

Firstly, is the Vin from the buck boost converter exactly the same as the Vout of flyback converter? What will it be if Vin from the buck boost converter smaller/ larger than the Vout of flyback converter?

Then, what exactly is the logic flow using the arduino UNO to write a program to control the duty cycle of PWM , with varying Vin and Vout of buck boost converter ( as different buck boost converters may be tested) within the preset range?

Finally, has anyone of you come across these problems and may provide me with some reference about it? Thank you so much! :blush:

Kevin ?

So your concept here is to use a switchmode converter as a dummy load - this is certainly a common practice in itself - in this case by using the output of this converter to augment the supply to the DUT.

Clever enough, but very complex as I think you actually wish to vary the input voltage to the DUT and have it maintain a constant output. Otherwise you would just be tweaking the control on the DUT itself and letting your converter absorb whatever the output voltage was. In the latter case, you need to determine whether you want the "load" to exhibit a constant current or a constant power drain.

My concern about such projects is that involving the Arduino in the feedback control of the converter will involve problems of stability, and you would be better using it to generate an analog voltage (filtered PWM) which simply became the reference for the converter - and similarly a reference for the forward converter which feeds the DUT.

Thank you so much! I guess I will take a easier step first, by fixing the output voltage in the buck boost converter ,meanwhile varying the input voltage in specific range , for the PWM generated by the buck boost converter, I would use the PWM signal generator instead.

So in this case, would it be necessary or feasible to adopt the filtered PWM in the flyback converter as you said? :) Thanks!!