Electrical suppression ?

[Whirlybird]

I have installed a car cam into the car and am getting electrical interference. The connector plugs into the cig. lighter, with the ignition on (not started) there is no problem, when started the noise starts.

 

Any ideas ?

 

Thanks

[ramjet]

I remember in the old days having to fit an ignition suppressor to the distributor to stop the annoying revving sound in the AM radio (remember those?)

 

Not sure what to do with your problem. Can you try and shield the camera in any way? Like a makeshift faraday cage earthed to the cars earth? Something to interrupt the electrical field from the cars electrics?

[mdw]

Mine had one of these fitted to the fuel pump when I got it which I think was for something similar.

.

[Whirlybird]

Michael, I remember the same things. But it was so long ago and I dont even know if that sort of thing is still available/used.

I know those suppressors used to be when the noise matched the engine revving.

 

Mine is a fairly stable noise, more like constant static.

[Alex Carter]

try running another earth lead from the cig lighter back to the battery out side the car to test if the whine goes away . failing that maplin should sell suppressors 

[Whirlybird]

Thanks Alex, can you buy suppressors which connect to the cig lighter ?

 

....and are you up early to go to Newlands now ?

[ramjet]

I would think that to use a suppressor successfully, you will have to find the interference source. If you use the AM radio example, the suppressor was not on the radio supply. It was on the distributor itself.

You can start by putting a suppressor on the cig lighter, but I am not sure if that is going to eliminate the interference you get once the engine is started.

[slewthy]

[molemot]

A suppressor is a capacitor that allows AC to pass through to earth ( or ground,depends on your country's nomenclature!) but keeps the DC isolated. Some capacitors are good for high frequency and some better for low. A 3 microfarad from the alternator terminal to earth and a 1 microfarad from the coil +ve to earth wouldbe a good place to start. Belt and braces..you could run the camera power through something like this...

http://www.ebay.co.uk/itm/10A-NOISE-SUPPRESSOR-FILTER-ELIMINATE-CAR-RADIO-NOISE-/330440858161

[Sparky]

Erik, I had the same problem - mine sounded just like that, and I solved it with a bit of Blu-tac.  Sounds stupid, I know, but it was engine vibration making one of the gimbal clamps rattle slightly against the cam casing.  Not saying yours is the same problem, but if the noise is independent of engine speed...

[Alex Carter]

Thanks Alex, can you buy suppressors which connect to the cig lighter ?

 

....and are you up early to go to Newlands now ?

 newlands ???? no i didnt go was just up feeding the baby 

 

the problem is when you have an av source that feeds from the cig lighter its either on the ignition side of the alternator circuit or perm 12v feed from the battery to take large amounts of power therefore its what they call dirty electric meaning its not filtered or suppressed in anyway so you will pic up interference if its a cheaper item thats plugged in . maplin will have suppressors for you but you may have to remove the cig lighter holder and solder it in the other side