If the economic argument for MPPT doesn't stack up, perhaps it's ability to match high voltage panels to a 12V battery will. Here I connect two 20W panels in series to produce a 72-cell 40W solar panel with a 35V max power point. Eventually, dispite the British weather's attempts to spoil the day, I got 40W from the panels. However, the buck converter components are now getting warm, possibly even hot.
By Julian
Youtuber, shed dweller, solar charge controller aficionado
Oo
I would certainly replace that 35v electrolytic cap. When they blow–they can be very violent! And you have the safety slots flat against a solid platform!! so watch out for a loud projectile!
The solution to your dilemma at the end of your video (too bright for oscillator but you need sun for the panels) is that you leave the panels outside and run wire into your house/lab and do your work in there. I know you would have to go outside to adjust the panels occasionally, but it would still be better 🙂
can i ask a favour julian ? just say i had 240v 1600rpm ac motor , now theres two questions i here what size inverter would i need to comforyably run it continuous ?
second quedtion – how would you with wires cheaply control the 12v input from 0 to max slightly overbuilt ?
Nice work.
But why are they in series?
i always believed that series gets the voltage op, and parralel gets the watt op?
This series of videos is awesome…am trying to do something similar for my final year university project…but with automatic pwm adjustment/mppt tracking.
And I think it's time to put current and voltage sensors on the battery side too, so both Watts in and Watts out can be measured. That will mean I can put an efficiency percentage on the display. It's one thing to extract maximum power from the solar panel, but quite another to deliver it to the battery without losing too much energy as heat.
Cheers!
I think the hot inductor and the ringing are connected, so hopefully it won't be necessary to beef up the inductor too much. I've bought 10 inductors from China, 100uH, supposedly rated at 6A. My philosophy for this project will be easily available, low cost components, so I'll have to make it work with them.
My main problem is lack of sunshine, so I might put my 100W panel on the test rig and do some tests under overcast skies.
Looks like it's coming along really well Julian.. 🙂 Do you think a brutal approach for the inductor might work – i,e. just wind it with heavier wire? Perhaps you could set up a line so you can send the power from those panels indoors so you can have them connected and use the scope too.
15kHz, so you probably are hearing it.
What is the switching frequency? There seems to be a high pitched tone on this video.