I'm having trouble designing a power supply circuit for a small microcontroller-based project.
The board I'm building will be powered by a 3.7V LiPo battery most of the time, but it could also be connected to a computer via USB. In that case the computer should be used as power source and the battery should be charged. The circuit to be powered requires around 5V and uses under 200mA.
I've put together various schematics from around the web and I've come to this, but since I don't know much about electronics I'm unable to tell if it would work or maybe burn...
[EDIT: I added a physical switch right after the battery to disconnect it and thus reduce leakage current when the system is turned off]
Here are the datasheets of U1 and U2:
So, here are my questions:
- Will this circuit work? What should I change?
- If the circuit makes some sense, are Q1 and D1 appropriate? (I have no idea, I found them in one of the many forums I just visited)
- Even if this circuit doesn't make any sense, how should the thermistor for the MCP73833 be placed? I guess I should stick it on the battery, but I've never seen a battery with something looking like a thermistor on it, so I'm curious.
Thanks for any answer!