I'm looking for ideas for a 5V power supply that will run from either 220V or 110V and have a battery backup. I want to use a standard 7AHr 12V sealed led acid battery.
I was looking at capacitive transformerless power supply but the unit I use pulls about 1.2Amps every now and then. Capacitive transformerless power supply can only supply low current outputs. It looks like I will have to use a transformer.
Is there a battery monitoring and charging chip, that say works with 12V. I can always use a DC/DC convertor to convert the 12V to 5V DC. I found it uses much less power that a 7805.