Kc9EYE Wall Wort Tests

Wall Wort Testing

After following a discussion on the QRP-L reflector, on the subject of voltage and wall worts, I decided to attempt some testing of my own. It was discussed on the reflector that the markings as to the output on the typical wall wort were really its full load capability and not typical. Measurements were taken on 2 power supplies I have lying around in the garage.

The first subject is a Kyocera model:TXACA0C01. The numbers implied on it are;

Here is what I got. The measurment device is a Simpson Model 260 VOM. The input was household lines at ≈ 115 VAC.

As you can see the good folks on QRP-L were correct. The no load voltage of the wall wort was more than 2 volts higher than expected. This would tend to suggest that external regulation would be needed if this supply was to deliver only the rated voltage. This case is not the extreme though. I leave that for my next subject.

The next subject is an Atlinks USA model:5-2558. The numbers implied on it are;

Here is what I got. The measurment device is a Simpson Model 260 VOM. The input was household lines at ≈ 115 VAC.

WOW! Check out that no load voltage. That is a little disconcerning. I would be a little worried about a device that had electrolytic capacitors rated only at 16 volts, after plugging this supply into it. To me this is really an eye opener. Maybe to anyone else to. Have you ever gotten a device from a fest or online auction that came with a wall wort charger or supply? Have you ever checked to see if it is of the appropriate design for the devise? I am checking mine now.

In conclusion, all moments of deciding to power that new radio transmitter or receiver (you just got done building) from a wall wort power supply should be thought over carefully. In all instances the wall worts output should be measured (don't take the units markings as fact) and the devices current consumtion known. Then whether or not the supply will fit the bill can be decided. In most cases I would think that external regulation would solve most issues, but I'm sure this will not be the case with some supplies.