Conservatively, Computer Power Supplies use a basic rectifier bridge to convert the incoming rotating line voltage to the direct voltage needed to power computer system circuits. Such rectifier works great with all common voltage waveform types. For that reason, most Line Interactive and Standby UPS systems and other bench power supply, based on affordable considerations offer non sinusoidal output waveform. These systems nevertheless, are vulnerable to drop load when powering brand-new computer servers build to abide by recent green oriented legal requirements.
Uninterruptible Power Supply (UPS) systems offer output voltage either from the energy mains (line) or from internal batteries by means of an internal DC to Air Conditioning inverter which converts the DC battery voltage to Alternating Air Conditioner waveform. Energy line voltage has a sinusoidal waveform with a grid frequency of 50Hz or 60 Hz. UPS inverter has a sinusoidal voltage waveform in a lot of Online UPS systems, and primarily a non sinusoidal, pulsed type (called likewise square, customized sine-wave, stepped) waveform in Stand By or Line Interactive UPS systems and bench power supply.
Pulsed waveform consists of the standard sinusoidal waveform with the fundamental frequency of the mains, and additional high frequency parasitic harmonics which do not contribute to the UPS output power. Current green oriented legislations, such as Energy Star need increasing computer server’s effectiveness and its power factor by removing input current harmonics. In order to comply, new server power supplies use an Active Power Factor Correction (APFC) circuit rather of the passive easy remedying bridge. We can expect most future standard computers to consist of APFC circuits as producers follow suit.
The brand-new computer systems created to deal with sinusoidal input voltage, as reported, drop in specific cases the load if the Inverter supplies a non sinusoidal waveforms. Contrary to the conservative passive rectifier circuits, which all consist of comparable input circuits; the particular design of the APFC circuit depends upon the producer. Hence, the specific behavior of a specific UPS with a particular computer can not be forecasted.
Both Standby and Line Interactive UPS system and bench power supply are usually powered from the energy line, which provides sinusoidal waveform as needed by the computer’s power supply circuit. Just when the line power stops working (or deviates beyond a permitted voltage window) the protected load is transferred to the internal Inverter.
The primary hazard with Line Interactive and Standby UPS systems with non sinusoidal inverters lies in the fact that its inability to safeguard brand-new computer systems is revealed at the very minute when the energy power fails and the Inverter starts. It’s like learning that the brakes in your automobile aren’t working when you are on a steep downhill.
For this reason, when purchasing a bench power supply at www.digperformance.com make certain that UPS Inverter supplies a sinusoidal waveform, to determine that it will have the ability to protect your present computer system and any future computer system you might require.