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 →
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 →
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 →
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 →
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, →
More than a year ago I was approached by an independent filmmaker about light dimmers. The problem fo them was how to get affordable light dimmers to control the film lighting. I was told that many independent non-commmercial filmmakers use a HarborFreight router speed control to dim the lights used for moviemaking. The reason is →
Resistance soldering is a soldering method that sometimes useful for hobby work. In this soldering methid an electrical current is flowed through one work piece, the joint and then the other work piece. Current through a resistances on the way generates heat. Most heat is normally generated on the joint because the resistance there is →
Assembly TV broadcasts TV program from Assembly computer festival starting Thursday 6. August 2009 in many channels (Internet, cable TV, DVB-H mobile television, 3G mobile video etc.). The broadcast has for many years contained Scene Quiz Show (the name has varied somewhat over years). It involves three contestants answering questions related to the event, demoscene →
A floating measurement reads the voltage between two points, neither of which is at ground potential. A most typical floating measurement done quite often is when doing voltage measurements with a battery powered multimeter. The floating insulated multimeter allows doing floating measurements of slowly changing signals easily. The advent of switching power supplies and motor →
Multimeters are very good tools to find out problems in electronics circuits and testing electronics components. Resistor measurement is found in practically all multimeters, capacitance measurement range is becoming more and more common and some high-end models can also measure inductance. Many multimeters have also possiblity to test bipolar transistors (Hfe measurement range), but I →