Anyone have any thoughts on this proposed scheme which is something I was thinking of for a dirt-cheap UPS, mostly for short periods when moving a Pico between hosts and/or PSU, exercises in 'show and tell' -It seems to me it should be possible to diode-drop VBUS down to a level which is below the maximum battery charge voltage and maximum current in all circumstances.
It's basically a trickle charger and, even if not charging the battery to full capacity, it should give some run-time, at least enough for what I am needing.
One issue beyond short run-times is extremely slow rate of charge, slow charge times, especially when the battery is discharged, but, again, likely not a problem for my use case.
The biggest issue is it allows complete battery discharge but that can be handled by turning the battery switch off which, yet again, shouldn't be a problem in my use case.
It's not CV, it's not CC, and is unlikely optimal, maybe "not the way to do it", but I am not really worried about that so long as it works, isn't actually dangerous, an explosive or fire risk.
Code:
__ O- .--|>|--|>|--|__|---.---O | __|__ \O--|>|--. VBUS | -.- | VSYS ....|...................|.............|...................... : | | | _____ : .-. | | | | | :5V |O|--^-------------------|--------|>|--^--| REG |---> 3V3 : |O|- | |_____| : |O|- | | :0V |O|----------------------^-------------------^------> 0V : `:' : :...........................................................:It's basically a trickle charger and, even if not charging the battery to full capacity, it should give some run-time, at least enough for what I am needing.
One issue beyond short run-times is extremely slow rate of charge, slow charge times, especially when the battery is discharged, but, again, likely not a problem for my use case.
The biggest issue is it allows complete battery discharge but that can be handled by turning the battery switch off which, yet again, shouldn't be a problem in my use case.
It's not CV, it's not CC, and is unlikely optimal, maybe "not the way to do it", but I am not really worried about that so long as it works, isn't actually dangerous, an explosive or fire risk.
Statistics: Posted by hippy — Mon Mar 04, 2024 5:48 pm