# Q&A（FAQ）Is it possible to use UPS as input source?

## 1. The waveform of the input voltage

The waveform of the AC input voltage is the sine wave. However, the input voltage is rectangular wave when UPS is used. Please refer to Fig. 1.1. If the input voltage is the rectangular wave, please consider the voltage operating the power supply and the rated current of the capacitor between the input line. Fig. 1.1 The input voltage of rectangular wave

## 2. The voltage operating the power supply

The power supply makes the DC voltage in which value is near the crest value of AC voltage by rectifying AC voltage for operation. The peak value of the input voltage whose value is the sine wave times the square root of two need to be applied to the power supply. Therefore, the input voltage range is shown as the following when UPS is used.

For example;

AC85V - AC 132V
Sine wave

120V - 186V (peak value)
Rectangular wave(UPS)

## 3. The rated current of the capacitor between the input line

If the input voltage is the rectangular wave, the ripple current of the capacitor between the input line is increased than the case that the sine waveform is applied. Therefore the ripple current should be considered whether it is smaller than the rated current of the capacitor. The ripple current depends on the voltage gradient and the kind of the power supply. Fig. 3.1 The input circuit