Hello all. New to the forum and not as knowledgeable as you fellows. Here's my question. I have a MP3 player that I can attach to my car stereo through an audio input. I would like to set up a power supply off the battery so I don't have to take it out of the car to charge. It requires 5v dc at 1.5 amps. Any help would be greatly appreciated.

 

Can u built the circuit by getting the parts if any one of us gave u a regulator schematic which will suite your needs.

Rifaa

 

Hello,

When using a linear regulator, you will have to "throw away" at least 10 Watts to get the 7.5 watts you need.
A switching regulator will have a much more efficient conversion.
Here is one at mouser:
http://nl.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMtwaiKVUtQsNWsVof5tyQvgWxlYSgAk//o=

See also the datasheet.

Greetings,
Bertus

 

Sorry for the delay in answering.
Bertus,would I need anything else with this? I fixed my profile.
Rifaa, I might be able to do it.

Thanks for the help
Vincent

 

Ok then try to get your hands on the regulator that Bertus suggested, a 5V one rated at 2A is more than enough. If you buy them don't just buy one, try getting two of them, just to be on the safe side if anything goes wrong, it's what I always do, having an extra saves a lot of time.
Other components you'll need depends on your way of swtiching the device, a device attached to your car stereo means you'll be using it in the car, am I right, if so tell me the how would you like to set it up, I mean when to power up, how to power up and the how capable are you to mess with car stereo harness.
If you think you won't just mess every thing up try to lay out a plan and tell me all the set up details and get some pictures of the stereo and it's connector options at the back and the car harness connectors available to you.
Setting up this professionally takes time and patience and if done right, it will be far better than any one doing it by paying him


Rifaa

 

Rifaa
I was planning on getting the power from a spare fuse under the dash, so it will turn on when I start the car. I was then going to get a plug set up (Female) so I could drill a small hole and mount it to the bezel that goes around the stereo. I was then going to make a new plug/cord to go from there to the MP3 player. I have set up a plug like I described for the input/output on the audio. As far as where to mount this device, I have not figured that yet. It will have to go under the dash or under the center console. I have a Honda S2000 and the space is limited. I'm adding some pictures, I hope they show up.
Thanks again. Vincent

 

Ah I see, is that connection the Audio out put to the input of the stereo.
Tell me these.
1. The fuse connection you were referring to, check whether you get DC 12V. When this is available, is it there when you switch of the car or not.
2. Do you need the charger to be able to switch off and on manually?
3. Is it possible to put small circuit, the size of cigarette box behind the stereo?
4. Do you need the MP3 player to power up when you open the stereo?

Till then I'll draw up a schema for you.

Rifaa

 

Riffa
Yes that is the connection to the audio input on the stereo.
1- I know that I have 12v dc that is switched on when I turn on the key. I just have to locate it. I know that don't sound good but I know that there is a source there that I can use.
2- No, The charger would be on all the time. I don't always use the Mp3 player so it could charge then.
3- I'll have to see, there is some space, but to really be sure I would have to have the unit in hand. Something the size of a pack of smokes could probably be tie wrapped some where up in there.
4- No, I manually turn it on and off.

Thanks Vincent

 

Find these componenets
1. 1 X 5V Regulator mentioned above
2. 2 X 10uf 16V , 105°C Electrolytic Capacitor
3. 2 x 100nf Ceramic capacitor
4. 1 X 1N4007 Diode
5. 1 X 470 Ω 0.5W Resistor
6. A Vero board by size not less than 4" X 4"
7. An inline 3A fuse ( preferably used in car, but if you have one inside then no need to get holder just a 3A fast acting fuse that could fit inside the holder will do nicely).

I presume you have solder and iron, with some experience in hooking up a circuit from a schematic.

I do not think you'll need a heat sink since the regulator is a DC to DC converter, but we have to figure that out once the MP3 player is powered from it.

The schema is on it's way.

Rifaa

 

Rifaa
Sorry for the long delay family health issues.Dad had heart surgery. I'm going to pick these up.Could you send the schematic? That would be great. I'm grateful for the help. Vincent

 

Vincent.....Is this that thread you were talking about.

 

Why does your MP3 player use a current as high as 1.5A?
Is it an old one that uses a hard drive?