Review on UL Listed 9V AC/DC Power Adapter For Arduino/Schwinn Bike A10 A20 A40 220 430 Elliptical Trainer/Crosley Cruiser CR8005A - Center Positive 5.5X2.1Mm Power Supply For UNO R3 - Only For Listed Model by Brian Thuo

No good for sensitive electronics (see update below). I paid a little extra hoping for good quality input for a DSO 150 based oscilloscope. The scope runs great on regulated 9V DC, but there is so much high frequency switching noise from this adapter, the noise overwhelms the signal being displayed with enormous spikes. Checked the output on my old Conar 250 scope which clearly showed the noise. Also, not a killer, but I expected something closer to 9V than the 9.5V it puts out. Guess I'll just add a home-made filter rather than return it.UPDATE: I have upgraded to 4 stars because I was a little harsh, and it turns out the oscilloscope itself has weak noise filtering on the input. This will be a great AC adapter if the manufacturer can add some filtering. The quality is really good otherwise and the noise pulses are actually only about 0.1 V and won't have any affect on most devices. They have responded to my complaint and seem eager to improve the product. It will work great for most uses, just not so great on very sensitive electronic gadgets.