Getting power supply from car ?

[AdvaRes]

Hi all,

I need to get a 5 v and/or 12 V power supply from my car for my GSM Charger. Which is the best way to get it ?

Thanks in advance

 

[daviddlc]

First thing is to know what is the maximum current consumption for each voltage.

Do you want to buy something or do you want to build it ?

 

[cameo_2007]

12V is readily available there,,you have to just tap it.
for 5,use a 5V regulator.. thats it .done.

 

[AdvaRes]

12V is readily available there,,you have to just tap it

Where ? From the radio ?

 

[pranam77]

Using this circuit you'll get 12 volts as well as 5 volts what you need. Take the input power from the battery. Be sure of the polarity. Hope it helps. Good luck.

 

[banjo]

Common place to tap off battery power on the car is the cigarette lighter. There are plugs available to easily connect to this.

Here in the US, there are many cheap cigarette lighter plug to USB charger devices. What these contain is a version of the circuit pranam77 has shown above. (The only two pins of the USB plug supported are +5V and gnd.) I would suggest getting one of these and doing some "surgery" to tap both the +12V input and the +5V output.

 

[AdvaRes]

Thank you all,

In need to know which wires to pick up from inside the car. If I use battery I 'll be obliged to guide wires through the car's window

 

[banjo]

Under the dashboard of the car is typically a fuse box or fuse panel. This is where to tap the wires. Start with the owner's manual. This should list the fuses. As already suggested, one good generic place to tap is the radio circuit. You can trace the power wire from the back of the radio and tap it there. If your current draw is small as in less than 1A, everything should be fine. (The worst that can happen is that you blow the fuse for the radio and have to replace it. )
If you do not want to use the radio circuit, look for a feature that is not implemented on your car. Something like, power antenna. Because the wiring harness must support all the features, it will have an unused connection in the fuse box.

 

[cameo_2007]

12V is readily available there,,you have to just tap it

Where ? From the radio ?

from the fuse box?