I need some major help !

[Charlie91]

Hey guys ! Basically, I've got a small project idea in which I'm going to integrate a Bluetooth device into a car radio circuit... And I'm looking for advice on how to supply a constant charge to the Bluetooth device with constant power without using a supply that's too high... Will I need to use a step down transformer or ? The Bluetooth device uses a 3.5mm aux cable to take charge usually but I'm not sure how to go about this at all....

I know I'm an idiot but I need some help !

Cheers, Charlie.

Ps. I will upload photos of the device and my progress when I can.

[Jimmy]

What is the device's model number?

what power does it need?

What are you trying to do?

Need as much info as you can give

[amspire]

Are you talking about some kind of Bluetooth device with an inbuilt lithium battery?  If you are going to build it into the radio, you will not want a battery power Bluetooth device. You do not want to have to pull out your radio every 2 years to change the lithium battery, especially as it will be powered by the car battery anyway.

I am not sure how well you can integrate a bluetooth device into a radio anyway. You need to be able to ask the bluetooth device to make itself discoverable so you can pair to it. You definitely do not want to have it permanently discoverable.

I assume you have given up on the FM transmitters as a way of getting music into your car radio, and so now you want to find a bluetooth device that you can connect directly to the radio's audio circuit.  It may be possible, but you can get great bluetooth radios with handsfree phone support for about $150. Is it worth trying to make a non-integrated bluetooth device work?

It would be much easier adding an audio input lead that you can plug into a standard earphone socket.

Richard

[Rerouter]

being how it would be fittied into the radio, you would power it off the accesory wire, i am going to guess this device runs off 5V and uses bugger all current, if so deadbug a lm7805 with some capacitors, and power the device off accesory,

or if the thing really draws some power, then one of these might be better (albiet pricier) http://au.element14.com/recom-power/r-78c5-0-1-0/switching-regulator-5v-1a/dp/1903040

I work with automotive tracking systems and instruments, and that 1 regulator so far has never failed on me,