What measurement is required to determine the output current of a transformer?

To determine the output current of a transformer, understanding the current transformer ratio is essential. The transformer ratio indicates the relationship between the input current (primary side) and the output current (secondary side). This ratio is determined by the number of turns of wire on each side of the transformer’s windings.

By knowing the primary current and the transformer ratio, you can calculate the secondary current effectively. The formula used here is based on the principle of conservation of power in an ideal transformer, where the input power (voltage multiplied by current on the primary side) is equal to the output power (voltage multiplied by current on the secondary side), minus any losses.

In contrast, other measurements such as voltage across the load, the power rating of the transformer, and the input voltage will provide different parameters (voltage levels, maximum capacity, and supply voltage) but do not directly relate to calculating the output current without the context of the transformer ratio. Therefore, knowing the current transformer ratio is crucial for determining the output current in a precise manner.