Switching Power Supplies

[quickstix16]

I am in the process of designing a robot. This robot will have an onboard computer and runs completely autonomously. I have a lithium polymer battery that will be powering a DC/DC converter that the computer will run off. what I would like to be able to do is switch from powering by the battery to powering from an outlet without the computer shutting down in the process so I may charge my battery up. Is this doable in a cost effective way?

 

[Reloadron]

You don't mention the computer you plan to use or the actual power requirements? Micro ATX motherboard maybe?

Anyway if you go that route you need to figure the power requirements and think about something like this to power it. Pick your poison based on need. Just remember that a 120 watt power supply, small as it is, will draw over 10 amps of 12 volt DC current under a full load. I hope this will be a large robot with a really large battery. You could attempt to build the multi voltage DC to DC supply but good luck with that. Next you want something like this, only on a much larger scale. Companies like Alarm_Saf and Altronix manufacture them. They maintain a charged battery and in the absence of line (mains) power automatically transfer to battery. Your DC to DC PSU would be fed by that unit.

So it is very doable, as to cost effective? That depends on what you define as cost effective.

Just My Take
Ron

 

[quickstix16]

well I am getting a micro itx. Our power requirements are of issue though. We are expecting 12 to 15A from our 24V lithium polymer battery and will be using a 360W PSU. As this battery gets low, we would like to switch out the power source without losing power to the computer so we may charge it back up. we would like to have the option of both a dc or ac back up system.