This is a DIY Headphone amplifier based on OPA2134 op-amp by Texas Instruments.
Apart from running headphones crystal clear, another advantage is that it can act as gain enhancer for my gainclone when watching movies from PC.
Cmoy DIY Headphone Amplifier – [Link]
This is a single digit up counter based on CD4518 (Dual decade counters) and CD4543 (BCD to 7-segment decoder) ICs.
Single Digit Up Counter with CMOS ICs – [Link]
This project demonstrates how pyroelectric IR sensor can be applied in the detection of moving object. Passive IR detector does not emits any IR light by itself. It is triggered by the variation of IR light that comes from warm & moving objects such as human body. Dogs, cats & other household pets have smaller bodies & do not radiate sufficiently strong IR to trigger the detector. Therefore it is pretty well immune to false alarm caused by pets.
PIR Motion Detector – [Link]
This project is a FM Radio basd on TDA7000 and LM386 integrated circuits. Schematic and PCB are available on the link below.
FM Radio Using TDA7000 and LM386 – [Link]
This project shows how to build a sensor to trigger a camera’s flash using a microphone or laser pointer. The brain of the project is an Arduino and it will activate the flash at accurate timing to capture precise moments. You can easily add new sensors, or even run multiple sensors at once. Since the triggering of the flash is done in software it’s easy to add delays, or make a more complicated triggering algorithm based on multiple sensors.
Triggering a Camera’s Flash with Sound and Light – [Link]
This article shows how to achieve wireless communication using XBee radios. The XBee radio is soldered on breakout board to be placed on breadboard. Two breadboards with a PIC on each is used and XBees are powered from 3,3V regulators. Source code is included on the link below.
Wireless Communication with XBee Radios – [Link]
Flavio Dellepiane has design a project for power sockets that can be switched automatically by an embedded Control Socket.
A range of applications is possible. For example, if an electric drill is connected to the Control Socket, the Switched Sockets will be powered each time the electric drill is running. In this case, a lamp could be connected to a Switched Socket and will illuminate when the drill is operating.
Flavio plugs into smart extension sockets – [Link]
This project is an audio amplifier rated at 100W. An audio amplifier is an electronic amplifier, which it used to amplify low-power audio signals (20 hertz to 20,000 hertz) to a level that suitable for driving loudspeakers. This amplifier uses the TDA7294 IC from SGS-Thomson which it’s a 100 watt operational amplifier. Check construction details on the link below.
100W Audio Amplifier – [Link]
Spintronics memories should store quantum information on the individual atoms, rather than electrons, according to University of Utah researchers. Look for atomic scale memories that use store information of the spin-state of atoms within seven years. [via]
Spintronics aims for atomic memories – [Link]