A ground loop isolator is used to take out the path of DC circuit from audio shield ground circuit. The preout audio part of the head unit is referenced to the outer metal chassis of the head, which means that the output reference for audio is connected with the head unit’s mounting position. Since all conductors offer resistance, a voltage drop through a conductor will result anytime a current flows through it.
Any kind of accessory such as electric motors and lights that are grounded to the ground loop isolator body will result to varying voltages across the body of the vehicle or conductor. If the voltage coming from the amplifier ground to the head unit ground could be measured, there would be a very slight voltage difference although they are both grounded. Worse, the small pulses are also produced by the alternator that is not filtered out entirely by the capacitors and/or battery. These minute pulses make noise, which varies with the alternator speed. A ground loop isolator schematic diagram could explain the concept more clearly.
Ground Loop Isolator for Video and CCTV
There is also a video ground loop isolator that can be used for CCTV camera applications and coaxial cable. The device has a BNC male to female input and output. The isolator is passive so it does not require any power input. The idea for the coaxial ground loop isolator is to prevent distortions of video signals resulting from video ground loops. The device reduces CCTV interference signals caused by ground loops and can be installed easily in a new CCTV camera system or to an existing one. The ground loop isolator for video/CCTV can be used if a video signal is transmitted by way of a coaxial cable through points that have varying ground potentials. The different ground potentials are usually caused by power line loads that are not balanced.
Installing Ground Loop Isolator for Video
A video ground loop isolator is line mounted with the video cable, which comes from the CCTV camera directly, and before any other device is connected to the coaxial cable. If there are a number of security cameras that are coming from a single area, the recommendation is to have a ground loop isolator that is in line with all the cables.
Why Ground Loops Need to be Isolated
A ground loop is a kind of system that connects circuits, which are made to have the same but in fact have diverse potentials, can cause electrical system issues or hazards since the soil resistance and electrical potential on different areas of the earth’s surface can vary.
If the system is a floating ground or one that is not grounded to earth, the voltages may be unstable. If a number of conductors that compose the circuit going back to the source have high relative resistance or there is a strong current running through them that produces a substantial drop in voltage, it can result to hazards in the electrical system which should be accounted for.