Request for float charger design 12v

[moosh]

Hi. Does anyone have a working 12vdc float charger design using a sealed lead acid battery and 240vac mains supply? The charger should normally power a 12 v circuit and trickle charge the sla battery which kicks in when the mains supply fail. You'll find this charger in card-access systems and alarm panels.

Any leads much appreciated.

[Breixo]

Hi moosh,

Look in the Microchip site for the Application Note AN714 'Wireless Home Security Implementing KEELOQ® and the PICmicro® Microcontroller'. It has a full documented Battery Charger for a 12V lead-acid battery from YUASA (for 4Ah or 7Ah) and a 5V 1A Power Supply with automatic switching between AC source and Battery source.

Bye,

[moosh]

Thanks for the lead, Breixo. Looks like it's a simple and usable design.

[crowinu]

do you need it with descreet components, once i found some dedicated ic's which does the job for float charging

http://focus.ti.com/docs/prod/folders/print/uc3906.html

[moosh]

Will the circuit work with a load on the power supply? The battery is being trickle charged and on standby.