Final answer:
To produce multiple voltages from a transformer's secondary winding, you can add taps to the secondary coil. The turn ratio formula is used to calculate the number of turns for each tap based on desired output voltages. Assuming high transformer efficiency, the output power is nearly equal to the input, from which maximum output currents for each tap can be calculated.
Step-by-step explanation:
To produce more than one voltage from the secondary winding of a transformer, you can create a secondary coil with multiple taps. These taps provide different lengths of the coil for use, effectively creating multiple transformers within a single coil. Each tap on the secondary winding gives a different voltage, which can be calculated based on the turn ratio formula derived from Faraday's law of induction.
For example, a multipurpose transformer could have a secondary coil with several points at which a voltage can be extracted. To determine the number of turns needed on the secondary to produce specific output voltages, you would use the turn ratio formula:
- Turns ratio = (Secondary voltage / Primary voltage).
- Secondary turns = (Secondary voltage / Primary voltage) × Number of primary turns.
Applying this to the transformer with outputs of 5.60, 12.0, and 480 V, and a primary coil with 280 turns and 240 V input, you would find the number of turns for each output by dividing each secondary voltage by the primary voltage and multiplying by the number of primary turns.
Furthermore, if we assume negligible resistance and that the transformer efficiency is near 99%, the electrical power output of the transformer almost equals its input. This allows us to use the power equation P = IV (where P is power, I is current and V is voltage) to find the maximum output currents for each used alone by rearranging it to I = P/V.