Car Electrical System to 5 Volts

[ericpeacock79]

Hi all,
I am working on a project to put an mp3 board in my car. I would like to be able to wire the board straight into the car electrical system.
here is the unit i am buying:
**broken link removed**

on the datasheet (what little there is), is says maximum 5v.

Specifications:
Operating voltage: 4.5V DC
Current: 1A/4.5V DC
Maximum working voltage: 5V DC
Audio Output Power: 3Wx 2
Speaker Load: 4 ohm
Remote control distance: 5 ~ 10 meters
Sound quality: 32k ~ 320k
Support Files: MP3 format
Support Capacity: 8GB / SD / MMC / USB​

what type of resistor would I need, or should I get some type of regulator?
converting the car electrical directly to 4.5v would be great.

I have in the past, wired LEDs into car electrical system, using the 12v resistors that came with the LED's (ebay sellers from china), but I have a feeling those little resistors wouldn't be enough protection for this device.

My plan is to integrate this little unit into the dashboard and run the line-out and/or speaker out to an pair of amplifiers. (one amp for front speakers, one amp for rear speakers)

which also brings up another question:
The speaker out ports on the data sheet say "4ohm speaker 3W x 2"
Is that output ok to run to a car amplifier?

any help and/or hyperlinks to the resistor/regulator needed would be greatly appreciated.

Thanks.

 

[colin55]

Buy a 12v to 5v cigarette lighter adapter. They are available in junk shops for $2.00 to $5.00 and will pass 1A. Use 1,000u electro to filter the high-frequency. You may have to adjust the output voltage.

 

[Jaguarjoe]

Almost all regulators like this put out 5.0 volts. To reduce it a little bit and get closer to 4.5, put a Schottky diode or two in series with the output. That'll bring down to 4.8-4.6 which should be safe.
eBay has small, inexpensive modules designed to do exactly what you want. Search power supplies or power converters. They're black cubes about the size of a Bosch relay.

3 watts is not a lot especially in a noisy car.

 

[MikeMl]

Also, I predict you will hear alternator whine. When you do, write back and we will talk about it...