alstroemeria @ instructables.com writes:
In this instructable we will be recreating a clock inspired by Alvin Aronson’s original design. When I first saw this clock I was very impressed by how clean an elegant the design was I immediately wanted to recreate this effect. I hope some of you feel the same and use this as a guide to be one-step closer to having one of your own
Digital/Analog Clock – Arduino + PaperCraft - [Link]
The LT3763 is a synchronous buck LED driver controller that delivers over 300W of LED power. Its 6V to 60V input voltage range makes it ideal for a wide variety of applications, including automotive, industrial and architectural lighting. Similarly, its output voltage can be set from 0V to 55V, enabling it to drive a wide range of LEDs in a single string. The LT3763 offers both input and output current monitors and limiting, which accurately control both input and output current. The LT3763 also offers accurate output voltage regulation as well as input regulation, useful for high impedance sources such as solar panels. Its constant current and constant voltage regulation makes it ideal for applications ranging from driving high brightness LEDs to battery and supercap charging
LT3763 – 60V High Current Step-Down LED Driver Controller - [Link]
Steven Keeping writes:
LEDs are a rapidly maturing technology that is making big inroads into the conventional lighting market. However, it is not the only new lighting technology in town. Organic LEDs (OLEDs) are now being considered as an option for some architectural lighting applications after gaining popularity as a display technology offering vibrant color without backlighting. OLEDs differ from conventional LEDs in that the electroluminescence is not derived from a semiconductor junction, but is generated from a film of organic compound. That makes OLEDs simple to manufacture into large, lightweight, and even flexible panels. However, despite some key advantages over traditional LEDs, the devices are not yet available as a commercial lighting option primarily due to low efficiency and high costs compared to solid-state light sources. This article describes the performance of today’s commercial-lighting OLEDs and compares it to established technologies, including LEDs.
OLEDs Move Closer to Mainstream Lighting - [Link]
Analog Device’s AD8232 is an integrated signal conditioning block for ECG and other biopotential measurement applications. It is designed to extract, amplify, and filter small biopotential signals in the presence of noisy conditions, such as those created by motion or remote electrode placement. This design allows for an ultralow power analog-to-digital converter or an embedded microcontroller to acquire the output signal easily.
The device can implement a two-pole high-pass filter for eliminating motion artifacts and the electrode half-cell potential. This filter is tightly coupled with the instrumentation architecture of the amplifier to allow both large gain and high-pass filtering in a single stage. An uncommitted operational amplifier enables the creation of a three-pole low-pass filter to remove additional noise. The user can select the frequency cutoff of all filters to suit different types of applications. [via]
Single-lead Heart Rate Monitor Analog Front End - [Link]
Bruno Putzeys writes:
I hate articles titled “Ten … myths debunked.” I would have to start by listing a round number of clumsily worded claims by the non-feedback camp who probably never said any such thing, and juxtapose some simplified school-book explanations to put them right. And after shooting, flaying and roasting alive my straw men and generally hammering home that feedback doesn’t work like that, I should then fail to explain why not. This would leave an excellent status quo where everyone has had their say and truths remain somewhere in the middle.
Negative feedback in audio amplifiers: Why there is no such thing as too much - [Link]
Mizchief100 @ instructables.com writes:
This project was my take on a DIY visual impairment aid that uses haptic and sound feedback. Basically it uses a distance sensor to measure how far objects are from it and then it beeps/vibrates accordingly (far away is slow vibrate/long beep delay and close up is fast vibrate/quick beeps). Real quick I’d like to acknowledge that I’m not the first to do something like this, but I have added many things to it that are different from designs I have seen. This isn’t being used for commercial purposes but just as a guide for others to make them for people who would actually benefit from having them.
VIA (Visual Impairment Aid) - [Link]
Electromagnetic door locks can be very easily implemented to almost any entry or security system.
We got used, that electromagnetic locks are a common part of entry doors to various buildings and offices. There are several types of such locks on a market, the most often they are a part of a doorframe. Each type has its pros and cons. From some point of view, the most universal are “external” types, which can be easily implemented into any door without a necessity of an intervention to a door construction. Even such types can be found in our offer.
Y280 and Y350 are bulky locks consisting of a module with an electromagnet and a metal plate from a magnetically conducting material, which shall be mounted to a door (usually an upper portion). After switching on a power supply, a strong magnetic field will be created, sufficient to keep the door locked. A force necessary to open a door is quite considerable (2800/3500N) and normally it isn´t possible to unlock such doors by a “violence”. A positive fact is that a metal plate also contains a backstop with a spring damping a noise at locking.
A representative of “to be built in” types, is the type Y100S. It operates on a principle of a metal stick ejection, that´s why even in this case is a holding force very high, limited mainly by a door construction. A big advantage of the Y100S is that the lock already contains a security sensor against premature lock activation. After applying a power supply on the lock, “nothing happens” – the lock gets activated only after approximation of a plate with a small permanent magnet (included in a package),i.e. only after the doors are closed. All three types operate at 12V, types Y280 and Y350 can also be supplied with 24V (overall power consumption remains approximately constant).
In case of interest, please contact us at firstname.lastname@example.org.
Lock it without a key – [Link]
Qtechknow @ instructables.com
Have you ever heard of TFT LCD screens? They are great ways to display information from your Arduino, or display pictures. The Arduino team just released an official TFT LCD screen with their new Robot at Maker Faire 2013. It’s very easy to get started with!! This tutorial will show you how to get the LCD up and running, load information from the SD card, and make a few simple projects.
The TFT LCD screen is a great way to detach your computer, and have the Arduino relay information that you need to know onto the LCD. A great part of the LCD is that it has a built in microSD card socket. You can store images on the microSD card socket, and even some text!
Your Image on an Arduino! – TFT LCD Screen Guide - [Link]
DOT. @ instructables.com
I and my friends like to have fun in summer. We like to fool around with music when we are camping. To make those parties more likely to professional ones I have made portable 9V LED strobe. For my surprise it really gives a big effect. I hope you will like it!
DIY portable LED strobe - [Link]