What must be changed when hooking up a buck transformer compared to a booster transformer?

When hooking up a buck transformer compared to a booster transformer, the critical difference lies in the configuration of the transformer leads, specifically the secondary leads. In a buck transformer setup, the goal is to reduce the voltage. This is achieved by reversing the polarity or configuration of the secondary leads as necessary to ensure that the output voltage is lower than the input voltage.

In contrast, a booster transformer is designed to increase the voltage, and the secondary leads are connected in a manner that adds to the voltage presented at the primary. Therefore, when converting from a booster to a buck arrangement, the adjustment to the secondary leads is essential for the transformer to function correctly.

Changing the voltage rating or connecting a series resistor are not standard practices for adjusting a buck transformer, and switching the primary leads wouldn’t address the specific requirement of voltage reduction in this context. Hence, modifying the secondary leads is the action that must be taken.