Electronics-Lab.com Blog

Does this LED sound funny to you? @ Evil Mad Scientist Laboratories… [via]

At first glance, these might appear to be normal 5 mm (“T-1 3/4″) clear lens ultrabright yellow LEDs. However, they’re actually “candle flicker” LEDs– self-flickering LEDs with a built-in flicker circuit that emulates the seemingly-random behavior of a candle flame.
In the close-up photo above, you can actually make out the glowing LED die on the left side, and a corresponding-but-not-glowing block on the right: the flicker circuit itself. In what follows, we’ll take a much closer look, and even use that little flicker chip to drive larger circuitry.

Does this LED sound funny to you? - [Link]

This tutorial covers the low cost DHT temperature & humidity sensors. These sensors are very basic and slow, but are great for hobbyists who want to do some basic data logging. The DHT sensors are made of two parts, a capacitive humidity sensor and a thermistor. There is also a very basic chip inside that does some analog to digital conversion and spits out a digital signal with the temperature and humidity. The digital signal is fairly easy to read using any microcontroller. [via]

Sensor tutorials – DHT11/DHT21/DHT22 low cost temperature/humidity sensors – [Link]

Yes, this video is really short, but it’s stunning once you know what’s actually going on: [via]

In the lab, University of Minnesota researchers show how a new multiferroic material they created begins as a non-magnetic material then suddenly becomes strongly magnetic as the piece of copper below is heated a small amount. When this happens, it jumps over to a permanent magnet. This demonstration represents the direct conversion of heat to kinetic energy.

more from ScienceDaily:

Researchers say the material could potentially be used to capture waste heat from a car’s exhaust that would heat the material and produce electricity for charging the battery in a hybrid car. Other possible future uses include capturing rejected heat from industrial and power plants or temperature differences in the ocean to create electricity. The research team is looking into possible commercialization of the technology.

…

To create the material, the research team combined elements at the atomic level to create a new multiferroic alloy, Ni45Co5Mn40Sn10. Multiferroic materials combine unusual elastic, magnetic and electric properties. The alloy Ni45Co5Mn40Sn10 achieves multiferroism by undergoing a highly reversible phase transformation where one solid turns into another solid. During this phase transformation the alloy undergoes changes in its magnetic properties that are exploited in the energy conversion device.

During a small-scale demonstration in a University of Minnesota lab, the new material created by the researchers begins as a non-magnetic material, then suddenly becomes strongly magnetic when the temperature is raised a small amount. When this happens, the material absorbs heat and spontaneously produces electricity in a surrounding coil. Some of this heat energy is lost in a process called hysteresis. A critical discovery of the team is a systematic way to minimize hysteresis in phase transformations. The team’s research was recently published in the first issue of the new scientific journal Advanced Energy Materials.

New Alloy Converts Heat Directly into Electricity – [Link]

Boostrap writes – [via]

Well, after some distractions (a small contract for NASA, and struggling to learn solidworks (AARG)), I got back to designing this device, made major configuration changes to simplify, improve reliability and improve precision, and have almost finished now. Reasonable CNC quotes permitting, I’ll have someone start making 2 or 3 prototypes in two or three weeks. So, last chance to add your two cents (or $64,000 worth) of ideas, and point out my worst ideas and design flaws.

I will attempt to post some photos here, and attempt to attach a PDF document that describes how it works. This is identical in principle to the original steps I outlined at the start of this thread months ago, but the configuration of the device has changed so the exact nature of many steps is somewhat different.

Sorry, but you’re probably going to need to maximize your window to see the images. If you’re willing to make a serious effort to critique the design, ask me for the solidworks 2010 files.

I usually think up really great, elegant names for things. This time I’m a total failure (!please help!), so the device is called “papec” for now (pick-and-place extra cheap). Sheesh.

DIY – Super-cheap pick-and-place device with ~1 mil accuracy – [Link]

Google just recently added voice search functionality to it’s Chrome browser and asked the folks over at Breakfast to come up with something to show off the new feature. [via]

The Verbalizer is an Open Source Bluetooth dev board that allows you to make a Voice Search device of your choosing. In the default configuration, touching the board starts a wireless Voice Search and prompts you to “speak now” to search. What I like is the fact that it is freely modifiable and includes downloads for the software/code, docs, schematics and laser cutter files. With all this information you can make one yourself. How awesome is that?

The Verbalizer – [Link]

civicbynature writes -

Thanks to jersagfast @ TheCustomGeek. He wrote an awesome menu program for adafruits 2.8tft breakout board. It has 5 different menu areas as well as a settings area for backlight brightness and sleep timers which saves the settings to EEPROM so the settings are saved even when there’s no power. Plus many more features. I have added many updates. It is now both UNO and Mega 1280/2560. compatible.

I have also added the ability to read actual Vcc voltages at the core using the Bandgap method For accurate voltage readings and sensor readings. And more. If you’d like to check out the latest code it’s available Here on my site.

Cool 2.8″ TFT Touch project… - [Link]

Oleg writes: [via]

What started as a quick re-factoring effort transformed to a major redevelopment, but finally all pieces fit together tightly and I am pleased to announce that initial release of USB Host Shield library ver.2.0 has been posted to github.

Some of the major improvements include the use of only 5 Arduino pins, 3.5x faster low-level transfers, and the ability to use USB Hub(s).

Make sure you stop by Circuts@Home to check out the full details like the current/future supported device classes and supported hardware versions .

USB Host Shield library Version 2.0 – [Link]

by Joshua Noble and undef

The receipt racer combines different in and output devices into a complete game. It was made during the “Let’s feed the future workshop”, part of the OFFF Festival in Barcelona on June 8th 2011.

RECEIPT RACER – [Link]

Open source 3D printers are multiplying like gray goo! here is an extruded-aluminum one. [via]

CubeSpawn – [Link]

Hacked solder paste dispenser [via]

Hacked solder paste dispenser – [Link]