Built a basic pixel plotting mode which displays the solar panel's IV curve. The curve has a distinct turning point (often called the knee) where maximum power is located.
By Julian
Youtuber, shed dweller, solar charge controller aficionado
This is absolutely fantastic!
Julian –
I have always struggled with the concept of impedence matcing to optimize power transfer. Anytime I post a question about it in a forum, etc., I get 96000 guys saying you match the amplifier output impedence with the speaker impedence, ie. 8 ohms to 8 ohms to get max power. I get what you are spposed to do, but not why. I mean, suppose you were told to match 8 ohms to 6 jumping beans ? it may work, but why ?
When I plug a light into the wall i don't have to worry about impedence matching. Why do I have to with spakers ?
I have watched your mppt #4 & #5 videos several times, and you use your LAMB to demonstrate that, with too few lights you get less power out of the solar panel, and with too many you also get less than peak power. But with the right number there is a maximum power transfer. This is the closest I have ever come to understanding impedence matching.
I would like to ask you a couple of questions, but it will require more single finger typing, and with 98, 000 subscribers I'd better check to see if you have time for me or not. I am older than you, and my time to come to grips with this issue is decreasing.
I love your videos!! I have to ask, though, how come you test with only a 20 watt panel ? I have a super-light portable and flexible 100 watt panel that probably weighs less than that. I use it for all my testing. At maximum efficiency (MPPT), I nearly had it running the compressor for a pretty large sized refrigerator. I love how you're doing your own programming and using a graphical display. I bought my own electronics to do all of that for me but, after seeing your videos, I feel like I want to do something of my own.
I have no solar panels; maybe some day, but I just love your videos. What a contribution of knowledge they are. Also, your reviews of ebay electronics are very helpful. I have myself purchased many of the items, mostly for tinkering and learning. Thanks for sharing some of your talents here.
Can you get 80W from an 80W solar panel (or 100W from a 100W panel)? That would be a good indication. What's your effeciency ratio? If the panel is generating 80W, is it all going to the battery or is some being lost as heat in the electronics?
Perturb and observe. The system continually makes small changes to the pulse width and watches for changes in solar panel power.
I also bought this module, but I don't remember it having a CC adjustment which you'll need to drive a LED. It could be that it's near its minimum, it might also stabilise once you load the output. Also, I can't see from this video what you're using to drive it: battery, linear PSU or switched mode PSU?
Sorry the two posts below need reversing to make sense of them .. regards ….
Stable .tbh I deal with this supplier a lot for his cc cv modules which are bang on accurate and thought he wouldn't even send it to me for 28p .also it's the only one I have with this type if wire inductor my others are like the ones you purchased .hope you get time to let me know your views ….keep up the posting there great …..
Great video always educational,could you take a look at a clip I put up today ,it was a cheap eBay win from but it's voltages fluctuates from 3.518v to 3.539 v I filmed in slow motion for you to try work this one out it's 5-30 v input 3-27 output I have 15v on input do you think it could be because I was very near to its min working voltage and would this small amout mv have and effect on the running of my 3.5 v 350 ma led would you suggest I up the out put volts and see if it becomes more
Ask any body. Heath Robinson is alive and kicking. Always there when needed. No matter where you are in the universe. He was even on Apollo 13.Llooking forward to your investigations.
Are you sure? I think you jest. Wikipedia says he died in 1944.
Next I will investigate what happens when you connect a solar panel to a 12 volt battery, and why that doesn't yield maximum power.
Heath Robinson did as still does a lot of good work. Never worry about getting his help. Fascinating video well done. Looking forward to the final unit.