Help me design a new car power supply project

[dave3141]

I want to sort of brainstorm some features and ideas for my next project.

At the moment I have installed a tv in dash, tv tuner, road angel, sat nav and phone charger, that all switch on when key is in the on position or engine is running, powered from cigarette lighter.

I want to change this to a seperate circuit where power is taken from the battery and the cigarette lighter is used to switch it on.

Ideas so far:

1. Have a time delay to allow charging and running of items after ignition is off.
2. Battery voltage level monitor and voltage display.
3. 3 operating modes - on / off / on only when ignition is on.
4. Also need a filter to block noise from alternator and engine.

Cant think of any more at the moment. Will probably try to keep as simple as possible......but might get carried away.

does anyone have any other ideas that I could add before I start designing it?

 

[kchriste]

2. Battery voltage level monitor and voltage display.

I assume by this you will have an automatic low voltage cutout circuit to prevent the battery from being killed if it is left on too long without the engine running.

 

[Russlk]

I believe that TV in the dash is not legal.

 

[dave3141]

I believe that TV in the dash is not legal.

Really??? I had probably better remove all the genuine renault parts I bought for the install then, as they must have beenn sourced illegally.

 

[mister_e]

In-dash TV are legal in most country. What is illegal is play movie while driving. BUT you can play movie IF AND ONLY IF the driver CAN'T see it.

As far as i'm aware of, there's no original in-dash TV but GPS.

 

[dave3141]

In-dash TV are legal in most country. What is illegal is play movie while driving. BUT you can play movie IF AND ONLY IF the driver CAN'T see it.

As far as i'm aware of, there's no original in-dash TV but GPS.

I am fully aware that watching tv is a bad idea while driving, hence the reason for wanting to design a power supply which can remain on when the key is not in the ignition.

 

[mister_e]

usually, most OEM tv have an handbrake input.. or sort of to disable the front screen while driving.

In your case it should be as easy as a toggle switch on the 'Switched 12Volt'. One side on the Battery, one side on the ACC or Ignition 12Volt.

 

[dave3141]

usually, most OEM tv have an handbrake input.. or sort of to disable the front screen while driving.

In your case it should be as easy as a toggle switch on the 'Switched 12Volt'. One side on the Battery, one side on the ACC or Ignition 12Volt.

It was a lilliput tv butchered for the screen, but not really wanting to discuss the watching of tv while driving laws, just looking for useful features for my power supply. I will have every component on a seperate switched power line .thanks.

 

[Overclocked]

To filter out some of the low Freq Noises, use a big cap and then a Voltage Regulator. To get rid of the High freq noises, use a Low cap, such a .1uf, .01uf, and maybe .001uf.

Voltage Monitoring, Use a Cheap Volt meter from bgmicro.com They cost about 8 bucks.