Q&A(FAQ) Is it possible to use a UPS as an input source?
1. Waveform of the Input Voltage
The waveform of a commercial AC input voltage is typically a sine wave. However, when a UPS is used, the input voltage may become a rectangular waveform (see Fig. 1.1).
When the input voltage is a rectangular wave, please consider the operating voltage applied to the power supply and the rated current of the capacitors connected across the input line.
2. Voltage Applied to the Power Supply
A power supply operates by rectifying the AC input voltage and generating a DC voltage whose value is close to the crest value of the AC waveform. The peak value of the input voltage (which corresponds to the RMS value multiplied by √2 for a sine wave) is a critical factor for the power supply. Therefore, when a UPS with a rectangular waveform is used, the applicable input voltage range is defined as follows.
For example:
AC 85V - AC 132V
Sine wave
→
120V - 186V (peak value)
Rectangular wave(UPS)
3. Rated Current of the Capacitors Connected Across the Input Line
When the input voltage is a rectangular waveform, the ripple current flowing through the capacitors connected across the input line increases compared with a sine-wave input. Therefore, care must be taken. The magnitude of the ripple current depends on the voltage gradient and the type of power supply used.
If you are planning to use a UPS in your system, please contact us in advance.