EEVblog Electronics Community Forum

Products => Test Equipment => Topic started by: toli on March 17, 2021, 06:26:17 pm

Title: BK Precision 8500 programmable electronic load control program
Post by: toli on March 17, 2021, 06:26:17 pm
I recently decided to experiment with Python so that I can use it for future projects. The best way to learn was to try doing something with it, so I've decided to write a simple program to control the BK 8500 electronic load.
The program is fairly simple but includes what I though would be useful to me.

I've placed the windows executable as well as the python source files along with additional information (all of which is also included as a readme file accompanying the source files) on my blog:
https://tolisdiy.com/2021/03/16/control-program-for-bk-precision-8500-dc-electronic-load/

I'm attaching the source files to this post, the executable itself is too large to add as an attachment, but can be downloaded from the blog page linked above.
A direct link to the file: https://tolisdiy.com/wp-content/uploads/2021/03/bk8500_controller.zip

Feel free to use the program as a whole or the bk8500.py module on its own. Hopefully it will be useful for someone else too :)

Edit March 25, 2021:
V1p1 is now available for download from the blog page link above (v1.1 source files are added to this post too).
The change log for this version:
– I/V/P readings have trailing zeros even if current value can be represented with low number of digits. If instrument is at higher range, last digit will be ‘0’ at all times
– Added measurements (I/V/P) logging. Logging starts when instrument is connected, and ends automatically when its disconnected. New connection will overwrite log file. Log file named “readings_log.txt” placed in same library as the run file
– Added plot of V/I history in a new tab (“Plot”)
– Added right click menu to V/I plot to clear history (plot and readings log file) and to save plot to snapshot
Title: Re: BK Precision 8500 programmable electronic load control program
Post by: HKJ on March 17, 2021, 07:01:58 pm
Another program that can control the load and many other devices is TestController: https://lygte-info.dk/project/TestControllerIntro%20UK.html (https://lygte-info.dk/project/TestControllerIntro%20UK.html)
It will log to csv files, draw curves and much more.
Title: Re: BK Precision 8500 programmable electronic load control program
Post by: Zucca on March 17, 2021, 07:04:03 pm
Lovely, please implement a discharge/capacity battery test.  ;)
Title: Re: BK Precision 8500 programmable electronic load control program
Post by: toli on March 17, 2021, 07:12:18 pm
Quote from: Zucca on March 17, 2021, 07:04:03 pm
Lovely, please implement a discharge/capacity battery test.  ;)

Its already there actually. Its not using the internal battery mode of the instrument as its limited (only works in CC mode and can't be read back from the remote interface).
Instead it integrates (all the time) the charge and energy since the counter was last reset (see the "capacity meter" portion on second page). It will work for CC/CV/CW/CR/Transient operation.

BTW, VOLTAGE ON SET and VOLTAGE OFF SET commands (all caps in the manual too, not my intention) can't be done remotely for the 8500 series. Therefore Vmin limiting is implemented in software and simply sends a command to turn off load when voltage drops below this value if enabled.
Title: Re: BK Precision 8500 programmable electronic load control program
Post by: toli on March 25, 2021, 02:50:50 pm
Updated to v1.1. Change log and download links available in first post of this thread.