DVD Player Lines from Generator

[graham_fuller]

Hi Guys,
I bought a DVD player for the kids to use on the way down to the island. With the engine running you get a few coloured lines appearing, its fine when the engine stops. Any last minute ideas. I thought of a condensor on the generator, but wasn't sure of the connections. Is there any other possibibilities?

Cheers,
Graham

[craiga]

Graham,

Its called RFI or Radio Frequency Interference and its usually introduced via the spark plug leads.

Do you use resistive type carbon leads? The original type were solid copper and would definitely cause this problem.

It could come from the coil - this can be corrected by placing a capacitor from the +ve side of the coil to ground.

Or to could be from the generator, use a ceramic capacitor from the output of the generator to ground.

Capacitors provide a filtering effect by short circuiting AC voltage to ground. This removes the 'spikes' in the cars DC electrical system, these spikes are causing your problem.

Good Luck,

Craig.

[graham_fuller]

Thanks Craig,
The cables are carbon not the original copper ones. I have a suppressor in between the Coil and Distributor sounds like I should put 1 between the positive and ground on the Generator. Where's the best place to buy them?
Cheers,
and thanks for the quick reply,
Graham

[craiga]

Graham,

You could get one of these from your local Dick Smith or Tandy or somewhere like Supercheap/Repco would have something designed specially for your requirement. So would your local car audio place.

You could also go to the wreckers and pick one up for free, as they will fit easily and securely into your pocket.  

MODIFIED:

have a suppressor in between the Coil and Distributor

Graham, there is a capacitor from coil -ve to ground, this is the condensor. For noise suppression you need one between the coil +ve and ground. The action of the coil primary winding collapsing when the points open can induce unwanted spikes in the cars 12VDC electrical circuit.

Cheers,

Craig.

[griffo]

Craig ,

Could this be causing my problem of the CD player going off for a couple of seconds  when I either brake or sometimes us the indicators ? ( note this doesn,t always happen just 8 times out of ten ) sorry for butting in on your post  Graham.

griffo.

[craiga]

Griffo,

Your problem sounds more like an earthing issue.

You should check that you have a secure earth from the CD player body (or earth wire) to the chassis, ensuring that there is no paint or other contamination between the earth lug and the body attachment point.

Good Luck.

Craig.

[griffo]

Craig,

Yep done that about three times now and still the same problem ,but I'll go and check it again just to make sure that i have a good earth . I also have tried changing the power source but still the same.

Griffo

[fccool59]

I assume you have a portable dvd player plugged into the cigarette lighter.
a poor earth can do it speaking from experience, also it could be picking up noise from the ignition or gen / alt.
you can buy filters from auto shops and car audio shops from about $8, you probably dont need a fancy one as they are more for high current drawing amplifiers.
you could wire it in behind the cigarette lighter or cut into the cord for the dvd player. Dont worry to much about destroying your cord as they are common and replacable and usually thrown out with permanent dvd installatoins. I think I have some spares.