Pete modifies a Longwei power supply to make a 5A, 32V variable current source instead. Along the way fixing the dangerous wiring and protective earth and adding current/voltage previews and output isolation. <br />Not bad for 3 op amps and a tiny perfboard. After testing Pete discusses the impact of the opamp choices<br /><br />00:00 - Intro<br />00:16 - recap the review <br />01:28 - Overview - sketches, as-is<br />04:00 - The plan<br />08:16 - Set-points on display not just actuals<br />11:12 - Need measurements<br />13:13 - The data found<br />14:00 - The build and review schematics and simulation<br />25:06 - Buzzing out<br />25:37 - power-up and add op amps one by one<br />25:58 - First test and thoughts<br />27:31 - Op Amp choices and implications<br />31:06 - Here it is finished and working (ok so board hanging out)<br />31:09 - safety improvments etc<br />31:42 - it didn't fit!<br />32:19 - possible improvments and precision improvments<br />36:06 - wrap-up, summary and outro<br /><br />PLEASE SUBSCRIBE on youtube <a href="https://www.youtube.com/channel/UCDGlaK7fh5ZY6nFLznaHgZw?sub_confirmation=1" target="_blank" rel="nofollow">https://www.youtube.com/channel/UCDGlaK7fh5ZY6nFLznaHgZw?sub_confirmation=1</a><br />Follow me on twitter for the latest updates <a href="https://twitter.com/PeterShersby" target="_blank" rel="nofollow">https://twitter.com/PeterShersby</a><br />My Youtube Channel <a href="https://www.youtube.com/channel/UCDGlaK7fh5ZY6nFLznaHgZw" target="_blank" rel="nofollow">https://www.youtube.com/channel/UCDGlaK7fh5ZY6nFLznaHgZw</a><br /><br />Related Information<br />The teardown and review <a href="https://youtu.be/VGTBzYbCbo4" target="_blank" rel="nofollow">https://youtu.be/VGTBzYbCbo4</a><br /><a href="https://odysee.com/@MOR" target="_blank" rel="nofollow">https://odysee.com/@MOR</a>:9/Teardown-Longwei-LW-K305D-power-supply-lbry:a<br />Guthub with Microcap simulation files (schematic) <a href="https://github.com/pshersby/longwei-current-source-mod" target="_blank" rel="nofollow">https://github.com/pshersby/longwei-current-source-mod</a><br /><br />Affiliate Links and Offers <br /><a href="http://share.octopus.energy/sunny-ape-959" target="_blank" rel="nofollow">http://share.octopus.energy/sunny-ape-959</a> <br />I recently changed to Octopus Energy for my UK electricity and Gas and had a smart meter installed, now I use Octopus Go Agile to reduce my bill. <br />If you are thinking of getting a quote, use my link and if you sign up you will get £50 back after your first DD payment, and I get £50 too which I can use to buy more exciting things for the channel. <a href="http://share.octopus.energy/sunny-ape-959" target="_blank" rel="nofollow">http://share.octopus.energy/sunny-ape-959</a> <br /><br />