Instructions for Soldering and Desoldering SMDs featuring up-close shots of fine-pitch soldering.
Surface Mount Soldering 101 - [Link]
By Steven Keeping:
An entire product and manufacturing infrastructure was built at the start of this decade in anticipation of demand from TV manufacturers for LED backlighting. TV makers were under extreme price pressure from consumers and demanded the LED makers came up with inexpensive backlighting solutions. (See TechZone article “LED Backlighting Enhances LCD TV Picture Quality.”) To support the nascent LED TV sector, the LED makers more than doubled manufacturing capacity and added a similar level of support for the plastic packaging used to mount the backlighting LEDs.
This article provides an overview of the mid-power LED sector with examples of plastic- and ceramic-packaged devices from leading LED vendors.
Mid-Power LEDs Offer Less Expensive Alternative for Lighting Applications - [Link]
rwilsford07 @ instructables.com:
A boost converter works in two stages, ON and OFF. In the ON stage the Semi-conductive Switch is conducting and current builds up in the inductor producing an electromagnetic field, this field stores energy. In the OFF stage the Semi-conductive Switch does not conduct and the electromagnetic field collapses. When the field collapses the energy stored in it can not escape through the Semi-conductive Switch so it goes through the diode and into the load/Capacitor at a much higher voltage. This happens several thousand times a second via the pulses from the NE555 Timer Chip and the result is being able to charge a high voltage capacitor from a low voltage source. Below is some aid for those of you who do not know electronics well.
DC-DC HV Boost Converter - [Link]
Movies look cool with those EKG (electrocardiogram), the one that beeps and detects heart activities. A few months ago, we had to shoot a hospital scene for our school project. We needed an EKG instrument. To keep the movie authentic, we didn’t want to fake the readings so we made the next best thing, a pulse monitor. Since my dad is a doctor he gave me some advice to design the pulse monitor.
Homebrew Arduino Pulse Monitor - [Link]
praveen @ circuitstoday.com writes:
In this article we explain how to do PWM (Pulse Width Modulation) control using arduino. If you are new to electronics, we have a detailed article explaining pulse width modulation. We have explained PWM in this tutorial using 2 examples which will help you learn how to control LED brightness using PWM and how to control DC motor speed using PWM.
PWM Control using Arduino – Learn to Control DC Motor Speed and LED Brightness - [Link]
This Instructable will teach you how to use the Arduino Analog ports. johnag @ instructables.com writes:
Digital Voltmeters (DVMs) are a special case of Analog to Digital converters- A/DCs.- they measure voltage – and are usually a function of a general purpose instrument called a Digital Multimeter( DMMs), commonly used to measure voltages in labs and in the field. DMMs display the measured voltage using LCDs or LEDs to display the result in a floating point format. They are an instrument of choice for voltage measurements in all kinds of situations. This instructable will show you how to use the Arduino as a DC DVM (Direct Current Digital Volt Meter).
Make a Mini Arduino programmable 4 channel DC-DVM - [Link]
Milen @ instructables.com writes:
Normally the Joule thief produces output voltage, which value is difficult to predict. Without load (the LED) I have measured voltages over 30 V. I wanted to create a Joule thief, which can be used to supply some small electronic devices, but having well defined and stable output voltage. There are known some solutions in which instead the LED load, a one-diode rectifier is used, and the output voltage is stabilized by the use of Zenner diode. I did not like this solution, because through the Zenner diode flows always a constant DC current, what reduces drastically the efficiency of the device and empties fast the supply battery. I was looking for other, better solution of the output voltage stabilization (limitation).
High efficiency regulated Joule thief - [Link]
Raj @ embedded-lab.com writes:
A light meter is used to measure the intensity of illumination in a given area. It is widely used in schools, warehouses, factories, hospitals, office buildings, museums, art-galleries, parking garages, stadiums, and many more, to measure and maintain proper lighting levels. The intensity of illumination is usually expressed in Lux or foot-candles. As the 4th project in our chipKIT tutorial series, today we are going to build a digital light meter using the chipKIT Uno32 board and the BH1750 digital light sensor. This project uses Digilent’s chipKIT Basic I/O shield for displaying the measured light intensity in Lux, foot-candles, and Watts/m^2 units.
chipKIT Project 4: Digital light meter - [Link]
Are you encountering any issues with developing a full-speed USB application on NXP’s LPC microcontrollers? This application note from NXP highlights some of the important issues that you need to be aware of for a typical full-speed USB application. [via]
Implementing full-speed USB on NXP’s LPC microcontrollers - [Link]
I stumbled on these lights at the local Home Depot store this weekend, and was intrigues by the price ($9.95 despite being listed at $20 online) and also the versatility. You can simply screw one into an exposed lamp holder and end up with a fixture instead of a bare bulb, while also using a lot less energy.Or you can use a supplied socket with a pigtail and wire it to a ceiling box. In my case, I was looking to improve garage lighting. A single 60W bulb was just not cutting it and I am not a big user of fluorescents.
Quick teardown- what’s inside a Home Depot 7in LED Easy light - [Link]