After reversing visual disturbance solution
Now more and more used in the automobile circuit of digital circuit. Some models in install rearview camera often run into a reverse image dithering, interference, or not to switch back. The following are the causes of such problems and solving methods. For your reference. (currently encountered are: tusk of superb, Octavia, soar team, magotan, BMW 5 series, Cadillac, lacrosse, etc.)
A, the cause of the problem:
Part of the German and American cars model, after the engine start, output voltage disturbance is bigger, to the reversing light power supply is not pure dc power supply, but a superposition of a pulse signal in the above, if there are conditions oscilloscope test are available, and will find similar is a square wave signal. If reversing camera with no filter (also known as rectifier), camera power supply line directly on the back light, is because the voltage unstable cause cameras don't work properly, the output of the video signal is not normal, so see is on a host computer has serious interference, jitter, or not to switch back.
Second, the solution:
1, relay, relay concatenated in between fire and rearview camera power supply, often using reversing light power to control relay switch), after add relay can solve the above problem in general. Because of the large joint relay wiring, if throw exists interference problem such as jitter connection: please click the following two
1) relay often directly take battery fire
(2) the camera power supply ground wire and video ground put body iron directly
More than two connection 99% can solve the problem, if there is a little water ripple can be reference to the next method with RC or LC filter circuit.
2, add filter circuit (without relay)
This method is on the reversing light power and level of filter circuit, the pulse power after filtering, formation of dc power supply (above the red line is the filtered waveform), camera power supply. So that you can completely eliminate the horizontal stripes on the interference.