Hi, I have a basic understanding of electronics and data logic.
It's been a long time since I've studied.
I'm building a portable iPhone charger.
It will be powered by 4 3.7v lithium cells,
2 cells in series(7.4v) in parallel with another 2 in series.
This 7.4v bank will be connected to an L7805CV regulator to give an output voltage of 5v.
This battery module is what my iPhone will connect to via its normal USB charging cable.
Now, inorder to recharge this battery bank, I will be connecting a 5v mini USB charging module so that I can for example recharge it with my ps3.
Now this is where I'm lost.... I need to wire the 5v mini USB charger to all the individual cells in parallel so that each 3.7v cell is being charged with 5v.
This confuses me though because 2 cells of each bank will already be connected in series.
I'm pretty sure the answer is a couple of diodes or transistors, but I can't work out how to do it. Could somebody please help and possibly draw me a quick circuit diagram. I would be very appreciative.
Thanxs.
Dylan. (77dylan77@gmail.com)
Also, I know these types of things are already on the market, but I wish to do it myself as I'm beginning a bit of a hobby.
It's been a long time since I've studied.
I'm building a portable iPhone charger.
It will be powered by 4 3.7v lithium cells,
2 cells in series(7.4v) in parallel with another 2 in series.
This 7.4v bank will be connected to an L7805CV regulator to give an output voltage of 5v.
This battery module is what my iPhone will connect to via its normal USB charging cable.
Now, inorder to recharge this battery bank, I will be connecting a 5v mini USB charging module so that I can for example recharge it with my ps3.
Now this is where I'm lost.... I need to wire the 5v mini USB charger to all the individual cells in parallel so that each 3.7v cell is being charged with 5v.
This confuses me though because 2 cells of each bank will already be connected in series.
I'm pretty sure the answer is a couple of diodes or transistors, but I can't work out how to do it. Could somebody please help and possibly draw me a quick circuit diagram. I would be very appreciative.
Thanxs.
Dylan. (77dylan77@gmail.com)
Also, I know these types of things are already on the market, but I wish to do it myself as I'm beginning a bit of a hobby.