This GU10 LED spot light is cheap (£3 including postage) and bright. But it’s also lethal! There’s a 50% chance of putting live mains within a few microns of the metal casing (which is what you’ll be holding when you insert it) and there’s no earth to protect you. It’s like playing Russian Roulette with 240v AC mains. This sort of thing gives new technology a bad name. Avoid it if you want to stay alive.
Dangerous GU10 LED Spot Light is Cheap and Bright but could Kill You – Seriously - [Link]
by Viktor Safronov:
Sometimes you may need a group of switches where, if any switch is activated, it deactivates the previously active switch. This Design Idea implements such a function with relays.
This “one and only one” function is often implemented as mechanical switches in which an actuator (usually a movable metal bracket) is used to switch contact groups on and off. When any switch is pressed, this bracket first deactivates all switches, then activates the pressed switch.
Exclusively select 1 of N relays - [Link]
An Arduino-compatible smart outlet designed to instantly turn your toaster oven into a reflow soldering station.
Advances in technology continue to shrink the size of components. Hobbyists, who have traditionally worked with through-hole parts, are finding these parts harder and harder to come by as more parts become unavailable in through-hole variants.
Soldering surface mount components with a soldering iron, while possible, can be a rather tedious task. In particular, when you’re working with densely packed pins like those of a microcontroller, hand soldering a board quickly becomes a daunting task.
Reflowster – Soldering Controller for Surface Mount PCBs - [Link]
Vishay Intertechnology Inc. have introduced a dual N-channel TrenchFET power MOSFET in a 2.05 mm square, thermally enhanced PowerPAK SC-70 outline.
The SiA936EDJ device is optimized for use in load and charger switch circuits, DC/DC converters, motor driving H-bridges and battery protection for power management in mobile devices. For healthcare applications it is suitable for non-implantable portable products and also for use with small brushless DC motors in handheld consumer electronics. It offers extremely low on-resistance of 34 milliohms at 4.5 V, 37 milliohms at 3.7 V and 45 milliohms at 2.5 V. The level of on-resistance at 2.5 V is 11.7 % lower than the closest competing 8 V VGS device while providing a higher (G-S) guard band and 15.1 % lower than the closest competing device with a 12 V VGS. A lower RDSON leads to more efficient designs which optimize battery life.
Dual N channel TrenchFET offers lowest RDSON - [Link]
This video reviews the two most common reasons why the output amplitude setting on a function or signal generator doesn’t match what is read on an oscilloscope. This can be due to an incorrect attenuation setting on the scope, but is most commonly due to the fact that the generator is not presented with the load impedance that it is expecting. To correct this most common case, you can either use the correct load impedance, or tell the generator what load you are presenting it with.
Why your Function Generator’s output voltage reading can be wrong - [Link]
In this tutorial Dave explains what Operational Amplifiers (OpAmps) are and how they work. The concepts of negative feedback, open loop gain, virtual grounds and opamp action. The comparator, the buffer, the inverting and non-inverting amplifiers, the differential amplifier, and the integrator circuit configurations are also explained. Then a practical breadboard circuit to demonstrate a virtual ground and the effect of voltage rail limitations.
EEVblog #600 – OpAmps Explained - [Link]
Texas Instruments unveiled a new Tilt & Roll Pixel (TRP) DLP pico chipset. According to TI, this is the smallest (at 0.3″, which is strange because the previous model was 0.2″) and most efficient DLP chip ever. It support HD resolutions (probably 720p) and can be used in pico projectors and wearable displays, augmented reality displays and other applications. [via]
The new Texas Instruments 0.3″ HD Tilt & Roll Pixel (TRP) DLP® Pico™ chipset is TI’s smallest, most power-efficient HD micro-mirror array and can generate 720p displays from compact applications, including tablets, smartphones, accessories, wearable displays, augmented reality displays, interactive surface computing, digital signage and control panels. The chipset delivers significantly higher levels of brightness and power efficiency, allowing developers to create a wide variety of applications and products in smaller form factors than ever before. The chipset’s fast switching speeds of up to thousands of times per second enable the world’s smallest true color RGB engines with 120Hz video performance.
TI’s smallest, most efficient HD pico chipset 0.3″ HD TRP DLP - [Link]
Raj @ embedded-lab.com
In this blog post, I am providing you step by step instructions to build a very simple temperature and relative humidity meter for indoor use. All you need to build this project are an Arduino Uno or compatible board, a DHT11 sensor, and a MAX7219 based 8-digit serial 7-segment LED display. The temperature is displayed in degree Celsius and relative humidity in percentage.
Step-by-step guide for making a very simple temperature and humidity meter - [Link]
Over a week ago I’ve got a notice that Texas Instruments (TI) is giving away a 50% coupon for MSP430_FRAM related devices. Without hesitation ordered their MSP-EXP430FR5739 TI experimenters board that price went down to $14.50 including free shipping.
MSP EXP430FR5739 FRAM based microcontroller board is interesting piece of hardware. It features FRAM memory instead of Flash which is claimed to withstand almost unlimited number of Reads and Writes. It is also faster. It can substitute an EEPROM on board. But it is not very popular technology due to different manufacturing. On this development board there is MSP430 microcontroller which has 16KB FRAM, 1KB of SRAM. It carries eight LEDS, MTC thermistor, 3 axis digital accelerometer, optional LDR, couple buttons. So this is great for many uses.
Experiment with MSP430 FRAM board via web interface - [Link]
joebell @ instructables.com writes:
With a little practice, you can make excellent double-sided PCBs by combining a laser cutter with chemical etching. The basic idea is: the laser cutter blasts away spray painted etch resist, then chemicals eat away the exposed copper. Once the copper is gone, the underlying board can be cut again with the laser to make through-holes. No drilling required! After some setup and practice, you should get reliable boards with 8-mil trace/space and hundreds of holes in about 2 hours. You can even cut internal routing and odd board-shapes!
Double-sided PCBs with a laser cutter - [Link]