your below the buck chips minimum start up voltage? your going to also have insertion loss that can be 0.1v to 2 or 3v depending on the buck IC used. if you want 5v then go with 10v of solar into 2 4.2v cells with a small bms. some extra cost and complexity but you gain reliability
@@britishtechguru your not the only one to hit this headache, I've been there lol. Lots of other companies with big appliances like TV's wanting to make them work over a wide range for multiple countries go the strange way of boosting the incoming mains voltage to around 400v, then dropping that back down buck style to the usual 3 5 12 24 that modern sets tend to like. This makes me wonder if you could use the board from a 1 cell power bank common years ago in the pound shops to get the few volts from the cell upto 5v, then reduce that to your exact requirements. Or.... Use the 5v into a tp4056 board to charge a cell to the the usual 4.2v, add another boost to 5v to drop back to 3 with a 1117 linear reg or another buck. There's the advantage of battery back up but it's getting a little complex...... Maybe too much so, I tend to overthink things.....
your below the buck chips minimum start up voltage?
your going to also have insertion loss that can be 0.1v to 2 or 3v depending on the buck IC used.
if you want 5v then go with 10v of solar into 2 4.2v cells with a small bms. some extra cost and complexity but you gain reliability
I was trying to get a stable 3v from a 6v solar panel. It seems the thing is no good for that.
@@britishtechguru your not the only one to hit this headache, I've been there lol. Lots of other companies with big appliances like TV's wanting to make them work over a wide range for multiple countries go the strange way of boosting the incoming mains voltage to around 400v, then dropping that back down buck style to the usual 3 5 12 24 that modern sets tend to like.
This makes me wonder if you could use the board from a 1 cell power bank common years ago in the pound shops to get the few volts from the cell upto 5v, then reduce that to your exact requirements. Or.... Use the 5v into a tp4056 board to charge a cell to the the usual 4.2v, add another boost to 5v to drop back to 3 with a 1117 linear reg or another buck. There's the advantage of battery back up but it's getting a little complex...... Maybe too much so, I tend to overthink things.....
@@lezbriddon Well, the zener seems to solve the problem but has yet to be implemented.