Digital audio isolation

Isolator for digital audio is needed in cases where coaxial S/PDIF digital audio link forms a ground loop in your audio system. Typically in coaxial S/PDIF connections the coaxial cable shield is connected to equipment cases. This arrangement easily creates ground loops which can cause noise problems in various places in audio system. A suitable

Build a Ground Loop Detector

Ground loops are a common problem in many experimental setups. A ground loop is an un- wanted closed loop of cables in the setup, most often through the ground system. Those ground loops are often hard to find and debug. A Ground Loop Detector document describes how to build and test a simple system to

Single point grounding issues

Remember that a real life return path for current is not an ocean of zero impedance. Some engineers draw every ground as a wire because even copper planes have impendance. This approach might be one reason that makes some audio engineers more think of using single-point grounding. By discarding ground planes in favor of thin

Build video isolator

Video isolation transformers are primarily used in CCTV application in fields of security, manufacturing, avionics and display. The video isolation transformer is an extremely broad bandpass 1:1 isolation transformer. Its hum isolation is very good and it can sustain very high noise voltages without degradation. Isolation decreases with increasing noise frequency. Video signals can transformer

Grounding outside

Inside building there are situations where you can see 60-115 V AC between different equipment grounding points. When going outside the building the voltage differences can between different grounding points can become larger. In electrical engineering, Earth Potential Rise (EPR) also called Ground Potential Rise (GPR) occurs when a large current flows to earth through

Lack of safety ground

Besides short circuit surge currents flowing on safety ground wire there are also other situations where you can see 60-115 V AC between the equipment cases. In the age of switch mode power supplies the safety ground has a new job, ie EMC line filter ground. When the power supply EMC filter is not connected

Safety ground is not reliable ground reference

I have written quite a bot of material on Ground loop problems and how to get rid of them. The ground loop related problems are often caused by small ground potential differences between different electrical outlets. Typically those ground potential differences are few volts or less. Not your fault article by Howard Johnson published in