by CsabaP @ instructables.com:
This Instructable shows you how to build a clap activated LED strip. The whole project is based on the Adafruit’s Secret Knock Activated Drawer Lock, where the user can record a secret knock pattern which will open the lock inside the drawer. I thought that I could use this to siwtch an LED strip on and off with a handclap pattern. So let’s begin!
Clap activated LED strip - [Link]
by BinksBrew @ instructables.com:
For a long time I’ve had old back up cell phones taking up space in my desk drawer. I was curious if I could put any of these old phones to some use. I can’t just throw them away so I decided to try and re-purpose one of them as a portable charger for my current smart phone.
Portable Charger for your Smartphone - [Link]
AC/DC modules Traco TMPS 03 with dimensions of 1“x1“x0,6“ represent a top-class solution of power supply with minimum space requirement.
Power supplies with a high power density (W/cm3) are nowadays offered by several producers. However, perhaps the biggest challenge is a miniature power supply with a power of say a few Watts. It´s because even these smallest power supplies need practically the same components like the bigger sources need (just less powerful of course), but dimensions of these “weaker” components are usually only slightly smaller than powerful ones.
In this case the new TracoPower TMPS 03 series brings a literally new dimension. Dimensions 1×1 inch (25.4mm) and a height only 15.3mm enable usage of TMPS modules even in devices, where every cm3 is precious.
A big advantage is, that the TMPS module is capable of a short-time (<30s) repetitive operation delivering up to 30% higher power (while maintaining average total power of 3W). This can be valued for devices requiring higher start-up current, or at driving small motors and similar. TMPS easily meets requirements for a small standby power consumption, as it only needs 0,15 W in the no-load condition.
TMPS series module can be sourced from “any” AC mains line (85-264VAC) and even from a DC line (120-370VDC).
One “inch” will provide you 3 Watts - [Link]
This project is a timer project and build around popular 555 Timer IC, It can be used for all application required a delay of up to 100 Seconds. Onboard board preset to adjust the required timer duration in range of of 1 to 100 Seconds, Tact switch SW1 to reset the timer and SW2 to start the timer. LED D3 works as power indicator and LED D2 to indicate timer operation.
Load can be connected to CN1 Screw Terminal, Out-put has both the operation normally Open and normally closed. Circuits works on 12V DC and consume approx. 100mA current. Very useful project can be used in various applications like water irrigation system, Kitchen timer etc.
Supply input 12 VDC @ 100 mA
Onboard start and reset tactile switch
Relay output: SPDT relay
Relay specification: 5 A @ 250 VAC
Relay state LED indicator
Preset adjustable range function
Power-On LED indicator
Screw terminal connector for easy relay output connection
Four mounting holes of 3.2 mm each
PCB dimensions 48 mm x 63 mm
1 to 100 Seconds Timer - [Link]
by Francesco Truzzi :
Some time ago I came across a new chip from TI, the HDC1000. It’s a temperature and humidity sensor with I2C interface and requires little to no additional components. It comes in an 8BGA package: we can all agree it’s pretty small.
Some of the peculiar characteristics of this chip are that it has a DRDYn pin which goes low any time there is a new reading from the chip (so you can precisely time your requests) and that the sensor is located on the bottom of the IC, so that it’s not exposed to dust and other agents that may false the readings. Also, it has an integrated heater that can remove humidity from the sensor.
So I developed a very small breakout board for this chip as well as an Arduino library (yay, my first one! raspberryPi and nodemcu might come next).
HDC1000 temperature and humidity sensor breakout, with Arduino library! - [Link]
The LT®3042 is a high performance low dropout linear regulator featuring LTC’s ultralow noise and ultrahigh PSRR architecture for powering noise sensitive RF applications. Designed as a precision current reference followed by a high performance voltage buffer, the LT3042 can be easily paralleled to further reduce noise, increase output current and spread heat on the PCB.
The device supplies 200mA at a typical 350mV dropout voltage. Operating quiescent current is nominally 2mA and drops to <<1μA in shutdown. The LT3042’s wide output voltage range (0V to 15V) while maintaining unitygain operation provides virtually constant output noise, PSRR, bandwidth and load regulation, regardless of the programmed output voltage. Additionally, the regulator features programmable current limit, fast start-up capability and programmable power good to indicate output voltage regulation.
LT3042 – 20V, 200mA, Ultralow Noise, Ultrahigh PSRR RF Linear Regulator - [Link]
This is easy to construct microphone pre-amplifier project using compact electret condenser microphone. The pre-amplifier is important building block of many audio communication systems. Circuit has been built around Op-Amp LM358.
– Power supply : 5 to 12 VDC @ 10 mA
– Output: Gain Approx. 100
– On-Board electret condenser microphone
– Header connector for connecting of power supply input and audio output
– Power-On LED indicator
– Four mounting holes of 3.2 mm each
– PCB dimensions 35 mm x 40 mm
MIC Pre-amplifier - [Link]
Impress your friend with the ultimate geek’s Birthday Cake! A hand-made open source electronic cake with candles you can blow out!
- Features 9 LED candles that you can blow on, to make them flicker and go out, like you do with a real birthday cake! Each candle blinks with random period and phase that depends on the intensity of the air flow
- Piezo sensor and a special air trap to detect air flow with astounding sensitivity using resonance effect
- Atmel ATTiny44 microcontroller on board with 4 kilobytes of flash memory and 256 bytes RAM
- Open source hardware and firmware. Can be re-programmed with an ICSP programmer or Arduino board via Arduino IDE
- Size 42 x 42 x 18 mm, weight 26g
- Powered by a single AAAA/LR61 battery (included)
- 3.3V step-up converter on board
- Ultra low shutdown current (less than 1 uA in deep shutdown)
- Hand-soldered using lead-free solder
BitCake – Electronic Birthday Cake - [Link]
by praveen @ circuitstoday.com:
Many guys here were asking for a frequency counter and at last I got enough time to make one. This frequency counter using arduino is based on the UNO version and can count up to 40KHz. A 16×2 LCD display is used for displaying the frequency count. The circuit has minimum external components and directly counts the frequency. Any way the amplitude of the input frequency must not be greater than 5V. If you want to measure signals over than 5V, additional limiting circuits have to be added and i will show it some other time. Now just do it with 5V signals.
Frequency counter using arduino - [Link]
by R. Colin Johnson @ eetimes.com:
A new type of transistor harnesses a new effect–called the quantum spin Hall effect — to create a topological field effect transistor (TFET) according to a Massachusetts Institute of Technology (MIT) researcher who recently moved to the newly formed Department of Materials Science and Engineering at Texas A&M University where the Texas Advanced Computer Center (TACC) confirmed the researcher’s results.
“We found that when deposited in a flat sheet just three atoms thick, our crystalline lattices exhibited a new electronic effect we call the quantum spin Hall effect,” professor Xiaofeng Qian told EE Times.
Transistors Prelude Quantum Computers - [Link]