9V battery down then up converter to 5V

[MrEd]

9v to 5v converter

I have kept my eyes open for a switch converter for a long time but haven't found a suitable one yet! Does anyone have any tips?
I'm looking for an efficient switcher that works as a down converter from 9V to 5V and as the battery gets below 5V it acts as an up converter to suck out everything of the battery.

If it has a built in circuitry to charge a 9V NiHm/NiCd battery as well then it would be perfect. Anyone seen a solution on that?

Eddie

 

[betanorm]

9v battery to 5v

I am not sure but I can remember that the IC 78S40 can do it down to 2.5V battery voltage.

 

[PaulHolland]

convert 9v to 5v

Hi,

What you are looking for is called a SEPIC converter.

Try National.com 's website they have a chip called LM3478 and LM3488 which you can use.. I know there are more vendors making chip you can use but nationals are easy to order.

Philips also makes a chip that you can use, it uses a switching freq of 600 Khz making its small and efficient.

Try also Linear.com...

regards,

Paul.

 

[jzo777n]

bring down voltage 9v battery

Usually a NiCd and Foam NiHm cell shouldn't be discharge to less than 1 V/cell.
I.e. for a 8.4V battery with 7 cells the minimum voltage is 7 V

A Sinter NiMH cell can self discharge to 0 volt, but if you can draw any current from it, I don't know.

Otherwise you are going to reduce the useful life of the battery

 

[MrEd]

9v 5v converter

jzo777n, very good point!

Eddie

 

[rambus_ddr]

how to convert 9 v to 5v

there are many Ldo to meet your requirement. ( such as TI, microchip)