3A Variable Bench PSU with Color Display


by SHARANYADAS @ instructables.com:

I am playing with electronics since i was a child and made numerous circuits.But still now,i didn’t made any power supply unit for general purpose use.So tired of making PSU for each circuit,I decided to make a stable Bench PSU for general purpose use with some enhanced features.I decided to made the core power supply analog controlled and extra features digitally controlled. So that’s why i choose LM350 linear regulator chip as the heart because 3A is sufficient for day to day use.

3A Variable Bench PSU with Color Display – [Link]

Electronic Live Capture Mousetrap

A mousetrap is a type of animal trap specialize to catch small animals, particularly rodents like rats, mice, hamsters, etc. This project is a kind of mousetrap that is intended to keep a captured animal alive. In this way, the hunter can release the captured animal later to the wild.

The PIC12F683 microcontroller acts as the heart of the project; it is programmed to meet function of the design. The sensor used in this project is a pair of infrared transmitter and receiver. An infrared LED connected to the GP2 pin of the PIC12F683 transmits continuous infrared signal to the TSOP1138 infrared receiver connected to the GP1 pin of the PIC12F683. To avoid the effect of ambient light, the generated signal at GP2 pin to the infrared LED is modulated at 38kHz frequency. Once the infrared beam is broken, the GP1 input changes, thus, the PIC12F683 reacts by triggering the GP4 pin connected to the BS170 MOSFET that act as a switch of the relay. The relay switch is set to shut the door when triggered. A push button connected at GP3 pin of the PIC12F683 is used for reset.

This project has a simple concept; the trap is built on a box fitted for a rodent to enter. The bait is placed inside the box to lure the rodent in. A sensor will be triggered once the rodent is inside the box, then a single door will shut lock behind the captured rodent.

Electronic Live Capture Mousetrap – [Link]

Makerarm – The first robotic arm that makes anything, anywhere


Makerarm just lauched on kickstarter. It’s a penknife for the DIY world, it can make almost anything by changing the toolhead!

A complete digital fabrication system for makers everywhere: 3D print, laser, carve, plot, assemble, pick/place + more on your desktop!

  • Makerarm works with interchangeable heads for countless applications.
  • It 3D prints: Makerarm is not confined to a box and can 3D print with both filament and resin.
  • It carves and mills: Makerarm includes high-speed desktop milling (light duty) and carving. You can mill on a variety of materials including plastics, wood, and soft metals right on your desktop. You can even hook up heavy duty flex shaft tools such as the Dremel Fortiflex to Makerarm for power-carving, grinding, or shaping applications (with speeds up to 23,000 RPM!).
  • It laser engraves: Makerarm’s high power 500mW laser head (405nm) engraves and etches on plastics, wood, leather, cardboard, and more.
  • It picks and places: Choose from vacuum pump coupled suction cups, electromagnetic heads, or grippers to carry out pick and place operations.
  • It assembles: With the assembly heads, you can automatically place and fasten screws, carry out gluing, and perform pick and place functions.
  • It’s a PCB fab: PCB milling, drilling, solder-paste dispensing, pick and place assembly (PCBA), and automated soldering take the hassle out of prototyping.

Makerarm – The first robotic arm that makes anything, anywhere – [Link]

The femtocell technology


by Slovati @ dev.emcelettronica.com:

Femtocells are basically low-power wireless access points that operate inside licensed frequency bands for connecting standard mobile devices with a provider’s network, using a broadband connection such as the DSL or a cable connection (basically using the best Internet connection available at that point). A femtocell is therefore an indoor base station that allows you to make phone calls with your mobile cellular using the Internet service avaialble locally; it is able to do that because femtocell is a transceiver that operates on the same frequencies of mobile phones, all within a home or office. When you connect with a mobile device to a femtocell, therefore, you do not use directly the provider’s mobile network, but you use the base station.

The femtocell technology – [Link]

Fastest, highest-resolution DLP chipset for 3D print/lithography


by Graham Prophet @ edn-europe.com:

With its latest micro-mirror-based light-steering chip, Texas Instruments says, applications developers can innovate with more than 4 million micromirrors to enable high throughput digital imaging applications.

Presented as its highest speed and resolution chipset for 3D printing and lithography applications, TI’s DLP9000X digital micromirror device (DMD) and the DLPC910 controller, offers developers more than five times the speed at continuous streaming compared to the existing DLP9000 chipset.

The DLP9000X DMD delivers the highest streaming pixel speed in the TI DLP Products portfolio at over 60 gigabits per second.

Example application areas for the DLP9000X include 3D printing, direct imaging lithography, laser marking, LCD/OLED repair and computer-to-plate printers, as well as 3D machine vision and hyperspectral imaging.

Fastest, highest-resolution DLP chipset for 3D print/lithography – [Link]

Single Channel SMD Relay Driver


Single Channel Relay Board is a simple and convenient way to interface a relay for switching application in your project.


  •     Input supply 12VDC @ 42 mA
  •     On Board 5V Regulator provides 5V output
  •     Output SPDT Relay
  •     Relay specification 5 A @ 230 VAC
  •     Trigger level 2 ~ 9 VDC
  •     Header connector for connecting power and trigger voltage
  •     Relay operations status LED
  •     Power LED
  •     Tiny Design
  •     Screw terminal connector for easy relay output connections

Single Channel SMD Relay Driver – [Link]

Open Inverter, an open source micro-solar inverter


Ken Boak has been working on an open source micro-solar inverter project:

We wanted to make a design that uses readily obtainable N-type FETS and an Arduino (more strictly a ATmega328P-PU on a breadboard) to generate the PWM signals and provide simple circuit protection, and load sensing. With the PWM signals generated in firmware it can easily be modified for 50Hz or 60Hz operation, either 115V or 230V operation and a wide range of battery input voltages.
We imagined that the final design could consist of an Arduino, an “Inverter Shield” containing FETs and driver ICs configued in a H-bridge and some voltage and current monitoring circuits. To make the inverter a 12V or 24V battery (or PV panel) and a 12V (or 24V) torroidal transformer would be added.

Open Inverter, an open source micro-solar inverter – [Link]

LiFePO4 charger


Markus Gritsch shared his LiFePO4 charger project in the forum:

Since I really like using LiFePO4 AA and AAA batteries in some of my projects, I finally gave in and built a dedicated charger for them.
Previously I used a lab power supply to mimic the constant current/constant voltage charging curve, which worked also fine. But after seeing Patrick Van Oosterwijck nifty LiFePO4wered/USB™, I thought it would be a bit more convenient to charge these batteries using USB.

LiFePO4 charger – [Link]

LTC4282 – High Current Hot Swap Controller with I2C Compatible Monitoring



The LTC4282 is an energy monitoring Hot Swap controller with dual MOSFET drive to enable 100A and higher current board designs. The LTC4282 ensures safe board insertion and removal from live 2.9V to 33V backplanes by controlling external N­channel MOSFETs to gently power up capacitors, avoiding sparks, connector damage and system glitches. High current hot-pluggable boards utilize parallel MOSFETs to reduce voltage drop, but all of these MOSFETs require large safe operating area (SOA) to ride through overcurrent faults. By controlling two matching current limited paths, the LTC4282 halves each path’s SOA requirements, reducing MOSFET costs in high current applications (>50A). The LTC4282 provides a rugged, compact solution for hot plugging and monitoring, especially in high power circuit boards in servers, network routers and switches, and enterprise data storage systems.

LTC4282 – High Current Hot Swap Controller with I2C Compatible Monitoring – [Link]

Protection Methods for Automotive Electronics Circuits


Jim Colby @ edn-europe.com discuss how to protect your circuits on automotive enviroment:

Along with the ever increasing drive for improved gas mileage, automobile manufacturers are striving to make their vehicles safer with each new design iteration. The safety features that are now available or standard on most vehicles, such as airbags, backup cameras, collision avoidance systems, and tire pressure sensors, have all drastically improved vehicle safety. The protections offered by these systems are obvious. But, there are also many unseen technologies that offer additional protection for the electronics systems in today’s vehicles.

As vehicles have become safer, so has the electronic circuitry that helps provide that safety. The advanced chipsets that are used in vehicles today are subjected to countless electrical hazards that are commonplace in the harsh automotive environment. Typical automotive electrical hazards or transients include lightning, electrostatic discharge (ESD) and switching loads in power electronics circuits.

Protection Methods for Automotive Electronics Circuits – [Link]