How to Maintain output voltage?

[zerostar]

Hi,

Battery Voltage become lower and lower since the use of time,

So can how can we maintain the out put voltage?

(I just seen some circuit can provide such functions)

 

[dougy83]

You can use a boost converter to give a constant voltage above the battery voltage.

You can use a buck converter or linear regulator to give a constant voltage below the battery voltage.

You can use a 2-switch buck (or 2-switch boost?), flyback or forward etc. converter to give a constant voltage that may be above or below the battery voltage.

 

[audioguru]

I use a "low dropout" 5V voltage regulator IC to power all my circuits that use a little 9 battery. Then the circuit is powered by a regulated 5.0VDC until the battery voltage drops below 5.5V.

An ordinary 7805 voltage regulator drops out (stops regulating) when the battery drops to 7V which happens very qucikly.

 

[crutschow]

For best efficiency and longest battery life you would use a switching regulator, such as dougy83 mentioned.

The simplest circuit is to use a linear regulator, as audioguru suggested.

 

[simonbramble]

... or ... just to be smart... you can use an inverter to generate a negative output voltage and put the battery in upside down. This avoids going through the nasty buck boost region

 

[gman123]

How about this idea? Link here.