Hi,

I have a device that is connected to a 24 VDC power supply.
I would like to get a battery that takes over the supply in the event of a power loss. I don't need to charge the battery when the main power supply is on.
the output current needed is very small, max 500 mA.

do you know if there are any standard PCB or IC that can do just this?

thank you,

Tibibs

 

Dual Diode is the most simple solution.

 

hi tibibs,
If the powered device could tolerate say 23.5V , you could use a medium power Schottky diode.

E

 

the device support easily a low voltage (23.5V). Actually it could even go down to 12VDC or so. My battery is actually a 18V battery for powertools (it will be easy to supply, replace, check the voltage status etc...)

 

hi
OK, Use two 1 Amp Schottky diodes or Si diodes as shown in post #2.

E