Electronics Design

Reverse engineering the of a ULN2003

I have many times found ULN2003 and ULN2804 transistor arrays to be very useful components when I want to control some loads like relays, small electrical motors or light bulbs from TTL circuits. I have for example used ULN2803 for many applications where I have needed to control something with PC parallel port. The interesting

USB and ground loops

USB was originally designed for desktop use, but it is increasingly used for industrial applications. For USB to survive in those environments, it needs to be made more rugged. It means that ruggedizing USB for ground loops and using better (more protection and better locking) connectors are often needed. Ruggedize USB connections for tough environments

Shields are your friend, except when…

Shields are your friend, except when… article tells that engineers just love to put shields on circuits, mostly as a defensive measure against signals on the outside getting into and disturbing our circuits, but they also keep signals inside from getting out and this really makes the folks responsible for EMI compliance happy. Even on

Arduino cellphone

Hackaday mentioned some time ago an interesting Arduino cellphone. The fact that you can build a cellphone around an Arduino is pretty neat: An Average Joe can build this thing with a minimum or background knowledge and without breaking the bank. Wow. The components include and Arduino Uno, GPRS shield from Seeed Studios, a TFT

DC circuit breakers

Knowing the electrical characteristics of direct current and its differences in comparison with alternating current is fundamental to understand how to employ direct current. Direct current presents different problems than alternating current with a regard to the phenomena associated to the interruption of high value currents since the arc extinction results to be particularly difficult.

Lightning protection

Every summer we get thunderstorms, with the accompanying lightning in Finland. It is expected that thunderstorms starts in few days. Varo! Torstaina salamoi article says that it is expected that next Thursday there will be (according to weather forecast) 5000-10000 lightning discharge events in Finland. Lightning is a massive electrostatic discharge between electrically charged regions

Ground Loop Tutorial

I was just pointed to a new interesting ground loop document few days ago. Ground Loop Tutorial is a tutorial on electrical interference with emphasis on ground loops. It distinguishes several different types of interference and discusses the underlying physics at a basic level. In the end there is a good list of Methods for

USB Fume Extractor Idea

USB Fume Extractor project combines a small craft box, 12v case fan, aquarium carbon filter, dc boost converter and some basic electronic components to create a USB powered fume extractor which treats your lungs to some clean air when soldering. Check the USB Fume Extractor video how the project works: USB Fume Extractor was designed

Noise Reduction and Isolation in Measurement

Grounding, or connecting some part of an electrical circuit to ground ensures safety for personnel and it usually improves circuit operation. Unfortunately, a safe environment and a robust ground system often do not happen simultaneously. It takes planning based on systematically understanding how electricity behaves in various types of circuits. Preventing electrical shocks and electrical