battery and wall cube adaptor device

[bubulindo]

I'm planning on building a portable device powered by a battery, but i also want it to be possible to connect a wall cube adaptor to power my device.

How can i do it without the need for a mechanical switch?

Best regards, Carlos Cardoso

Best regards, Carlos Cardoso

 

[zeitghost]

Is the battery a rechargable one?

rgds
Zeit.

 

[bubulindo]

It could be, but i don't want to include a battery charger chip.

Since it is ment for commercial use, people might try to charge batteries that aren't ment for that charger. Like placing an NiMH battery in a place for a Li ion battery!

best regards, Carlos Cardoso

Best regards, Carlos Cardoso

 

[zeitghost]

There's always those hideous d.c. power connector thingies you find on wall wart power supplies.

Looking in a catalogue, I see that the pcb mounting socket is available with a built in disconnect switch that would allow you to disconnect the battery while the wall wart is powering the device thus preventing any charging of the battery.

rgds
Zeit.

 

[bubulindo]

In what catalogue did you saw it?



Best regards, Carlos Cardoso

 

[rbulsara]

How about using diodes in series with each source, arranged so that two sources will not feed in to each other. (Both cathodes meeting at the positive pole of the load).?

Just a thought...not an electronic expert.

 

[dhwilliams]

Go to

http://www.rswww.com

and type "486-678" in the Search box, this is a standard dc connector which has a built-in switch that allows you to use either the internal battery or the external power supply - you should be able to get the same thing from any Electronic Component supplier. If you mean that you don't want any mechanical switch, even the one built-in to the socket, then rbulsara's 2 diodes method will work. Just make sure the power supply is a higher voltage than the battery and remember that the diodes will drop about 0.7V