"Constant Voltage" Transformer Power Delivered
This calculator provides line loss with 2-conductor cable
on a constant voltage line.
Equation used to calculate the data:
Ploss = 10 * Log [1 - ((2 * RL) / (2 * RL + (Vline squared / Prated))]
RL = (Rref / 1000) * D
Where:
D = length of wire used
Ploss = ower loss in dB
Prated = power driven on line
RL = wire guage resistance
Vline = voltage on line
Many people don't realize that 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 "70V 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
