By PSW Staff • June 1, 2010 A transformer labeled for use with a specific voltage will work just as well at other voltages. This calculator provides power delivered from a transformer tap when driven with other than the rated voltage. Example: You are installing a distributed system with very long lines. To overcome line loss, you select a 140-volt system. Which transformer tap will feed 10 watts to a loudspeaker with a 70-volt transformer? 1. Enter values for both “Voltage Rating of Transformer” and “New Voltage” 2. Either: – Enter a value for “Tap Rating” to calculate the power output from the tap at the new voltage. – Enter a value for “Power from Tap” to calculate the correct transformer tap to achieve the desired power at the new voltage. Equation used to calculate the data: Pactual = (Vnew squared / Vrated squared) * Prated Where: Prated = transformer tap value Pactual = new power from tap Vrated = voltage rating of transformer Vnew = new voltage Comments Leave a Reply Cancel reply Your email address will not be published. Required fields are marked *Comment Name * Email * Website Tagged with: Amplifier World Audio Crown Live Sound Reinforcement · all topics Subscribe to Live Sound International Subscribe to Live Sound International magazine. Stay up-to-date, get the latest pro audio news, products and resources each month with Live Sound.