eTeknix Power Supply Testing Methodology

Jake Sedge / 13 years ago

There are three main elements to our testing equipment which are each there to provide us with different pieces of information to judge the quality of a power supply:

SM-268 Active Load Tester

This Sunmoon product is the heart of our testing equipment, therefore it is very expensive! Costing £880 it is not the cheapest bit of kit- but if PSU testing is to be done properly, this is the kind of kit you need to invest in, which is why only a few sites are capable of doing proper’ PSU reviews. The SM-268 is a very versatile piece of equipment, however it’s main job, in short, is to draw power from the PSU to simulate system load. The power from the PSU is converted into heat by the unit which is exhausted out the back to our hotbox which is mentioned later. The unit is capable of drawing a total of 1222W from the 12V rails, 304W through the 5V and 201W through the 3.3V making a grand total of 1721W total maximum draw- we have yet to see a PSU phase it yet. The SM-268 also features accurate voltage readings, a BNC connector for an oscillioscope and many other features. The best thing is the ease of use, simply plug the connectors into the front panel, input the loads in amps and start the PSU up. It’s scary to work with at first, but perfectly simple when you get the hang of it!

GW Instek GPM-8212 Digital Power Meter

This device is a lot simpler (and smaller) than the load tester but is extremely useful. At £450 it is still not cheap, but using this top-quality lab equipment ensures accuracy, reliability and ease of use. This device is installed inline on the kettle lead that powers the PSU and measures the wattage being drawn by it:

The unit is powered by it’s own power supply. The main information we need from this power meter is the power being drawn by the PSU to calculate efficiency as well as the power factor. It can also display the frequency, voltage, and current as well as many other bits of information. As you can see, the sockets on the front allow probes to be installed and can be used in a similar manner to a multimeter.

Stingray DS1M12 USB Oscilloscope

This device is the cheapest, yet arguably the most important piece of equipment in the setup costing £125. This oscilloscope does the same job as a traditional scope, but instead of displaying the information on a screen surrounded by controls, it interfaces with it’s own PC software that displays the information on the screen in the form of a waveform.