In which scenario would it be inappropriate to use a buck-boost transformer?

Using a buck-boost transformer is typically designed for situations where there are voltage adjustments needed, particularly to correct undervoltage or overvoltage conditions. However, when faced with a variable load exhibiting significant voltage drop, a buck-boost transformer may not be the most effective choice.

This is because a buck-boost transformer is primarily intended to handle relatively steady loads and make minor adjustments in voltage to accommodate slight variations. In scenarios with significant voltage fluctuations caused by variable loads, a buck-boost transformer may not be able to regulate the voltage effectively. The fluctuations can result in a rapid change in load demands, which could exceed the capabilities of the transformer to keep the voltage stabilized.

In contrast, other scenarios like constant loads or steady-state operations provide a stable environment where the buck-boost transformer can function optimally, making it well-suited for those conditions. Occasional load fluctuations are generally manageable for a buck-boost transformer, allowing it to still provide voltage correction effectively.