Good day members
I'm making a small 12V ups for routers,modems etc..
Main power supply is a 12V 2A wall power adaptor.
Secondary power supply is a single 18650 connected to tp4056+voltage boost module.
I'm planning to use IRF9530N p channel mosfet for switching.
I've attached a rough schematic to show the connection.
Please let me know about possible issues with this arrangement.
Thanks
Why do you need a switch?
Why do you need a switch?
to switch between wall adaptor & battery (when mains power down)
The switch can be eliminated choosing the right voltage for the charger.
Doy you reaaly need to switch between them if you have protective Shottky (or other type) diodes?
I've had a stupid charger/powersupply adjusted to 13 V connected to a small 12V lead battery for 6 years now, driving router, wifi access point, network switch, modem and a raspberry pi (using a 12V to 5V DC converter) for 6 years. Foolproof and no circuitry needed.
I'm talking about the same.
Thanks all for the input
Mains supply is quite unstable here.
When there is repair, we wont be having any power for 8 hours.
I'm using this as a learning experience too.
like the others said, the easiest way is to build an adjustable power supply, set it on ~13-13,8V (which is no problem for common 12V devices) and hold a Pb battery in parallel on float charge.
Calculate the current drain from your devices and choose an appropriate Ah rated Pb-battery and you're fine to go also for longer than 8h