get 12V from 2 9V battery

[Transistorman]

how to get it ?

 

[antknee]

Use a voltage regulator. You will lose power, the difference between voltage in and voltage out multiplied by output current. i.e. (18-12) x Iout. If this is a mains device don't worry about it, if its a battery device you might want to think of something else.

 

[Transistorman]

thanks , i will searching for the regulator
note : i use the regulator is not for microcontroller
but for linear IC and it needed 12v power supply
( im running out of DC JACK )

 

[Nigel Goodwin]

What EXACTLY are you trying to power?, 9V batteries are mostly of very small capacity and very expensive, MUCH better to use AA's instead.

 

[Transistorman]

or we can just use 9v - 12v amplifier if can ? :?

 

[wizard]

thanks , i will searching for the regulator
note : i use the regulator is not for microcontroller
but for linear IC and it needed 12v power supply
( im running out of DC JACK )

It does not matter If the IC is a linear one till its highest current draw is not more than the maximum current delivering of the regulator chip itself. If you want to use 78XX regualtor chips then please make this consideration that maximum power deliviering of those regulators is just between 1A to 1.5A.

 

[antknee]

You could use 4 AA batteries with a DC-DC converter/booster. This will take the 6V from the AA batteries and output 12V. THey will last longer and be cheaper than 9V batteries.

 

[Transistorman]

It does not matter If the IC is a linear one till its highest current draw is not more than the current delivering of the regulator chip itself. If you want to use 78XX regualtor chips then please considder that MAXimum power deliviering of those regulators is just between 1A to 1.5A.

thanks i will take a look of your idea