X-bit labs

Topower Power Supply Units Roundup (page 3)

Category: Other

by Oleg Artamonov

[ 11/07/2007 | 11:31 AM ]

Together with an APC SmartUPS SC 620 this power supply worked well at loads below 350W. This refutes the myth you can learn at many Web forums that all PSUs with active PFC have problems with uninterruptible power supplies. In actual fact, only some older PSU models, the TG500-U35 cannot be counted among, have such problems.

The PSU features superb stability of the output voltages. None of the three tracked voltages leaves the allowable limits at any permissible balance of loads.

At a load of 480W the output ripple amounts to 43 millivolts on the +5V rail (the allowable maximum being 50 millivolts), 65 milliseconds on the +12V rail (the allowable maximum being 120 millivolts), and 18 millivolts on the +3.3V rail (the allowable maximum being 50 millivolts). It means the PSU meets the output voltage ripple requirements.

The PSU is cooled with a 135mm Globe Fan RL4T S1352512MB that has a translucent impeller but lacks any highlighting.

The fan is attached to the PSU case via shock-absorbing rubber spacers to minimize noise. I should note, however, that it is the air flow and the buzz of the bearing and impeller that create most noise you hear from a fan. The transfer of vibration to the PSU case doesn’t add much noise to that.

As you could see above, the PSU sticker shows a diagram of correlation between the fan speed and the output power but it has nothing to do with reality. The fan starts out at a speed of 970rpm and accelerates to 1731rpm as the load grows. The PSU is average in terms of noisiness. It might be called quiet if its fan worked at a constant speed at loads below 250-300W.

The PSU is 80% efficient, which is a rather average result as today’s PSUs go. The power factor is above 0.95.

The Tagan TG500-U35 is a good product. It is free from serious drawbacks, delivers stable voltages, offers a sufficient selection of connectors, and is not very noisy. This PSU can be a good choice for people who need a quality and high-wattage power source. My only gripe is about the screened cables and rubber connectors. I think that power connectors and cables should be handy rather than pretty, but it’s just the opposite in this PSU.