Testing Power Supplies with Electronic Loads (video #146)

All our gadgets run with electrical power. And they usually demand constant voltage. We use batteries or some sort of regulated power supplies to deliver this energy. Today, we will look at procedures to test these power sources.
We will cover:

  • The basic principle of testing of power sources like poser supplies or batteries
  • The problems associated with it and its resolution
  • I will show you my new IT8512A+ electronic load and how it works
  • At the end, we will test a very nice small DSP5005 power supply with the procedures we learned

Electronic loads are able to adjust current to a set value and stabilize it, also at changing voltages

Basic diagram of a Electronic Load

If you are interested in a comparison between two USB electronic loads, you can watch my video #75

And a (unfinished) project with a bigger Electronic load:


There is a problem if we want to measure larger currents: The voltage is not displayed correctly.

This can be changed by using either a Voltmeter connected directly to the power supply or by using a more expensive Electronic load with Remote Sense capabilities, like the IT8512A+ used in this video, or its more professional “parent”, the BK8500. Or a Maynuo M9712, which is comparable with the IT8512A+. You can also get models with less maximal current, which are cheaper.

We test a DSP5005 Power supply and use what we learned. For that, we connect the IT8512A+ to a PC.

Connection cable between the IT8512A+ and the PC

You can either buy the original one:


or build your own.

I used a male 9 pin Sub-D connector to connect the cable to the load

Then, I used a normal FTDI USB to Serial connector, which I switched to 3.3 volts

Now I could connect the cable to the USB port of my computer. But this would create ground loop issues. This is, why we have to use an additional USB insolator

This device creates a complete electrical separation between its two USB ports up to 1500 volts.


To install the software, you first have to install parst of Labview (in this order):



And then, you can install the ITECH software


I had some issues that some issues. Buttons were not displayed:

Fortunately, you can press the buttons and they display the information.

Add your device, and off you go.

I kike the power supply i used for the test and purchased also some other models from this supplier. This is, why I add an overview about the different power supplies of Hangzhou Ruideng Technologies for your convenience:

(Affiliate links to support the channel, no extra cost for you)

Electronics Load store: http://s.click.aliexpress.com/e/RFybmIa
RD official store: http://s.click.aliexpress.com/e/2fmMJqR