How to use DS1052E to measure quality of step-up/step-down converter - Page 1
Forum section: electronics / beginners

author: extasic
author_rank: Newbie
timestamp: April 14, 2016, 11:22:51 am
content: Hi,I just got step-up/step-down converter board (IC + some parts) I ordered from an asian supplier. I don't have much information about it, only some basic specs:- fixed 3V3 output voltage- input range: 1V8 - 5V- max 500mA output currentMy goal is to use it to convert the power of a li-on battery to the 3V3 required by one of my circuits. As I own a Rigol DS1052E and a programmable DC power supply, I wanted to test the "quality" (linearity of output, occurrences of peaks or dips) of the module. I want this mostly for fun and to train using my scope, not for a high-quality blog reviewSo this is how my approach I came of with looks like: I wanted to output some voltage curves between the specified input range to the module, and add a 60k resistor as load between GND and the output pin of the converter. I would then attach the two channels of the Rigol to GND and the input and output voltage. Any issues with this test setup?My main problem is now how I should setup the Rigol measurement. I have played around with repetitive patterns from a function generator (sine/square waves etc.), but I have no idea how I should- setup the trigger (there hopefully is no "edge" or "pulse" within the constant 3V3 output)- do a long-time measurement (maybe around 30s, do I need a computer attached to the scope for this?)I already configured the scope to use the "Long Mem" memory depth, but all captures are only fractions of a second when I stop them.Do you have any idea how I can realize such a test with this scope?Thanks in advance and best regards

author: danadak
author_rank: Super Contributor
timestamp: April 14, 2016, 11:43:19 am
content: I think what you are looking for is in effect a strip chart recorder.This is a an example used that acts as a data logger, might be useful.https://hackaday.io/project/810-30w-240w-halogen-led-balcony-solar-lanterns/log/2495-measuring-ui-and-up-charts-of-unknown-solar-panelYour 60K is not much of a load, just a thought.Regards, Dana.

author: extasic
author_rank: Newbie
timestamp: April 14, 2016, 02:00:37 pm
content: thank you for the link!I'm not quite sure if I understand this part right:QuoteSo does he use the function generator as external trigger to create regular "measurements" and this is the "strip chart recorder" part you propose? Or how should I realize this using the scope?

author: danadak
author_rank: Super Contributor
timestamp: April 15, 2016, 11:46:13 am
content: A strip chart recorder is for relatively low data rate sensor monitoring.https://www.instrumart.com/products/4675/fuji-electric-phe-strip-chart-recorderA DSO can act as a recorder at very low sweep / sampling rates, and also canoutput those values in MS Office compatible files, like excel, for external plotting.So DSO could output and collect in a file samples over very long periods of time,and then you use file to manipulate and plot the data.The software to use would be LabView or Matlab to do sample capture, display.Here is a python based approach -http://www.cibomahto.com/2010/04/controlling-a-rigol-oscilloscope-using-linux-and-python/Regards, Dana.

author: extasic
author_rank: Newbie
timestamp: April 23, 2016, 09:17:59 am
content: Quote from: danadak on April 15, 2016, 11:46:13 amgreat, thank you very much