Unlike all the other universal DC supplies I’ve seen, this one is voltage regulated. This means there’s a semiconductor control that keeps the voltage constant across a wide range of loads. Without regulation, the voltage of a DC supply will only be correct when it’s providing its rated current output. If the load is less, the voltage will rise and could damage the device being powered.

The supply is rated for 1200mA and can run on AC at 100 to 240 volts. Under a 580mA load on the 12v setting the voltage fell from 12.06v to 11.82v. On the 6v setting it fell from 5.68v to 5.48v. This is pretty good. With the regulation, there’s no risk of damaging the device being powered, as long as you set the voltage and plug polarity properly.

Compared to another of my universal supplies, this one causes a bit less buzz when powering a little self-amplified speaker. I had to hold the speaker right up to my ear to hear the noise.

Since it’s a switching power supply rather than a transformer, it’s small and light compared to other universal supplies I’ve seen. When left plugged in with no load, it doesn’t get warm at all.

The AC plug prongs fold down for easier storage.

The only criticism I’d offer is that the selection of plug tips could be better. I’d like to see a couple of the headphone-like plugs, and a 9-volt battery connector. If it had 12 plug tips like some other supplies, it’d be a perfect product. But I think you can buy other tips of this type; it seems to be a standard.

I may buy a couple more of these.

This is light weight unlike other cheap adapters. Weighs about the same as an ordinary cellphone charger. Approximate dimension: 7.5cm x 4.8cm x 3.5cm.

Output voltage measured 9.22V~9.23V while selector was set at 9V and input current at 119.2V to 119.6V. This is an impressive ~2.55% variance (without considering the fact that the input voltage was not exactly 120V). A new 9V alkaline battery measures 9.29V.

I bought this to replace the one that came with my router. My wireless router’s original adapter goes really hot in use. Since I needed to keep it on everyday, I was afraid that it would explode and burn my house someday. This one works pretty well, the temperature keeps in a normal range and it is adjustable for other products.