# How to make 3 pins power ( V+ GND V- ) from 12v Battery ?

#### Tùng Sơn Lê

Joined Jun 21, 2017
2
Hello everyone,
I am doing a DIY speaker which i want to have a micro , a guitar input with a bluetooth amplifier ( TDA7492 Bluetooth ) . Everything was ok until i met the problem about power for opamp to gain for micro & guitar , it requires V+ GND V- , and i just have the 12v battery for TDA 7492 .

So how can i make 3 pins power ( V+ GND V- ) from 12v Baterry ?

Thank you very much ,
Tungggg

#### EM Fields

Joined Jun 8, 2016
583
Hello everyone,
I am doing a DIY speaker which i want to have a micro , a guitar input with a bluetooth amplifier ( TDA7492 Bluetooth ) . Everything was ok until i met the problem about power for opamp to gain for micro & guitar , it requires V+ GND V- , and i just have the 12v battery for TDA 7492 .

So how can i make 3 pins power ( V+ GND V- ) from 12v Baterry ?

Thank you very much ,
Tungggg
Use an isolated DC to DC converter to generate the negative voltage and tie its positive voltage to battery minus/ground.

#### JUNELER

Joined Jul 13, 2015
183
Hi,
Im trying to find an IC for your needs but i cant find. Another solution is to create a circuit using a transformer.
Primary side is input like 110vac or 220vac as you like. On the secondary side a 12vac o 12 vac wiring.Center tap secondary.
Rectify a positive 12v and a rectify negative 12v if you know how to do it . Or else you can buy a ready made available power supply with an
output of your needs.

#### Alec_t

Joined Sep 17, 2013
12,311
Since the -ve supply is used only for the opamp, instead of a true GND you can use a virtual ground .
The 0V and +V rails are then treated as -V and +V respectively, avoiding the need to generate a true negative supply. The opamp's signal input and output would each require an AC coupling capacitor.

#### blocco a spirale

Joined Jun 18, 2008
1,546