Electronics Design

Resistance soldering

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

Scene Quiz Show lights

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

Floating measurements

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

MOSFET testing

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

Controlling dangerous things safely

Fire When Ready – A Pyro-Electric Safety Primer is a great document on issues around controlling dangerous things electrically. The document tells the techniques used on pyro/fireworks electrical control. Quite similar practices are used in other control applications where potentially dangerous things are controlled using electrical circuits or electronics.

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

Agreement on Cell Phone Chargers in E.U.

European Commission has reached a voluntary agreement with some of the biggest names in the electronics industry to introduce a common charger for cell phones that fits all models. New phones configured to use the standardized chargers use a micro-USB connector for charging. Information on this USB charging connector is available at USB Approved Class

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