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map maker
03-13-2010, 09:09 AM
I need a long life for my board of education USB Rev D running on the BS2.

Can i hook up a small 12V battery (like a motorcycle battery)ˇto the 9V clip

I cant find any info on the regulator on board.

Any help would be appreciated.


ˇ

Mike Green
03-13-2010, 10:14 AM
Look at the schematic for the Board of Education on the Parallax webstore page for the product. It shows that the regulator is an LM2940. You can find the datasheet for that with a simple web search. That model regulator can operate with an input voltage up to 26V, so 12V would not damage the regulator. There's a separate issue with power dissipation. Any input voltage above 5V has to be dissipated as heat and the amount of power dissipated depends on the current demand on the regulator. The Stamp itself doesn't take much (10's of milliAmps), but anything connected to it will increase that and other drains on the Board of Education's regulated power supply will also increase that. The regulator will shut itself down if more than 1 Amp is drawn from it or if it gets too hot.