So I just got myself a NOAC (Super Joy III) and a 3.5" TFT LCD Car Rearview Monitor.

I think modding wise I should be ok, but the main worry I have is powering the system. I don't want to mess it up and send too much power to something and fry it. so I was hoping someone can help me with what I should use or if I should add in a type of regulator. (I'm really not sure whats needed.

The screen says it uses 3W and has a DC 12V Power Supply
here's the screen I bought. http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0413064598

Any help and suggestions would be great!



oh yeah, ill also need to add in some speakers too, ill have to look around and see what I can find.

What type of batteries are you going to be using?

That screen is pretty cheap. Can you post pics of the insides when you get it?

You can power the NOAC from a 7805. That will provide 5 volts. It should work.

The screen may need a little more juice to turn on. Maybe like 5.3 V or something, really not sure. All these screens are different.

In order to get sound you will need to add a audio amp. If you are a DIY you can build a circuit around a LM386.

I was thinking about using some camcorder batteries if there powerful enough. Something with a protection circuit that protects it from over charging.
That is if something like that will have enough power, i don't know much when it comes to batteries.

As soon as the screen comes in ill post some pictures of it. though I'm not expecting it to come in for a while.

when it comes to building my own DIY stuff I'm not very good at it, especially since its hard to get some of the parts I need around here.
I just figured I would just go and buy a descent amp or something from a store.

I'm familiar with that screen type, it's the same one I've used on many a projekt

The optimum input voltage for that kind is 6v or more. Although, it's possible to make it work on as little as 3v.

Best part about the screen is that you don't need a regulator for it. So you can just hook any battery straight up to it, as long as the input doesn't exceed 15v.

As for an audio amp, you should DIY anyway! What better way to get better at it? If done right, an LM386 based amp can be quite tiny (I've seen them made no bigger than a quarter!).

Ohh awesome! that really makes my life easier

I guess ill give DIYing an amp a shot. Any instructions/schematics you can link me to that would be good to use?

When in doubt, google it!



Stuff like this pops up!

Surprisingly, now that I look at it, that is actually pretty close to the circuit I use for my devices, only I didn't use the cap between pins 1 and 8 to keep the gain at 20...I also used a 20k pot, with a 100k resistor connecting from pin 3 to the input lead on the speaker (this is because I don't have any 100k pots that'll work/look good in a portable lol).

I just got the screen in today! Id post some pictures but sadly all the pictures I take are too blurry :p

So does anyone have any suggestions for what I should use to power it? I just want to make sure I can get something that works great but wont be too powerful.