Transformer-based buck-boost

Question 14 It is much easier to find off-the-shelf inductors. So why is a transformer-based buck-boost even worth considering ... 

In other words, the transformer-based Flyback behaves just like an inductor-based Buck-Boost, with the difference that the output voltage is V0R, not V0. So decreasing V0R calls for a decrease in D. However, the same input power still has to be drawn from the switch. So if the width of its waveform decreases, the height of the waveform must increase. Which means that the inductor current must also increase. So, decreasing V0R could also end up decreasing efficiency. That is why for most universal-input Flybacks, the best Vqr compromise is about 90V to 105V. 

Answer The answer to that may well depend on whom you ask These terms are often used interchangeably in the industry. However, generally, most people prefer to call the conventional inductor-based version a (true) buck-boost, whereas its transformer-based version, isolated or non-isolated, is called a flyback. ... 

---