Audio and Video

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

New volume standards for MP3 players

According to Reuters news article the European Commission has issued new volume standards for MP3 players on Monday this week. The new standards will require that MP3 players will play at a safe volume by default. There will also be a health warning so consumers who choose to override the default settings know the risks.

Troubleshoot ground loops with clamp multimeter

A normal way to troubleshoot ground loops problems in audio systems is to listen to the audio signal at the mixer with headphones. If the buzz exists at the mixer then do the following: One by one, disconnect the inputs and outputs to and from the mixer and note if the buzz decreases. This same

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

Build humbugging transformer

Ground loop elimination in video systems does not always ask for a complete isolation of the grounds. There are passive hum suppressor transformers that will very effectively remove the hum from the video signal, but do not affect the video signal otherwise. Those special transformers act like a common mode coils, which stop the annoying

Filter injects noise

RC filter or amplifier’s lowpass filter at the input of a delta-sigma ADC is normally put there to reduce noise. But sometimes adding a filter can produce a noisier digital output than without that filter. Using an analog filter to inject noise article tells that it is as easy to eliminate higher-frequency noise with an

Augmented Reality in a Contact Lens

Researches are developing a new generation of contact lenses built with very small circuits and LEDs. They promises bionic eyesight in the future. Bionanotechnology researcher Babak A Parviz writes about his research toward producing a computer interface in a contact lens at IEEE Spectrum article Augmented Reality in a Contact Lens. The author states that,

Cool 3D Projection on buildings

3D Projection on buildings video at http://www.loodzwaar.com/2009/07/21/3d-projection-media/ shows amazing visuals that can be made by projecting 3D graphics to buildings. Take a look at this video.

Power and Grounding for Audio and Audio/Video Systems

Power and Grounding for Audio and Audio/Video Systems – A White Paper for the Real World is a “White Paper” that attempts to cut through the confusion and set out a collection of good engineering practice that is both safe and effective. This 37 page technical document is worth to read for everybody who works