The bq2404x series of devices are highly integrated Li-ion linear chargers devices targeted at space-limited portable applications. The devices operate from either a USB port or AC adapter. The high input voltage range with input overvoltage protection supports low-cost unregulated adapters.
BQ24040: Single Cell Li-Ion Battery Charger With Auto Start - [Link]
This document describes the development of Cytron Technologies DIY (Do It Yourself) Project No.11 (PR11). This project will use PIC16F876A to control NPN power transistor (BD135) further drive DC brushless fans, LEDs and buzzer when the certain temperature was detected. The value of temperature always displayed on a LCD screen. Circuit schematic and PIC source code will be provided.
Temperature Control System using LM35 - [Link]
Prepare your drawing on your favorite software -> Upload your files -> laser does the job -> get your package. That’s how easy you can obtain your own acrylic parts.
MiniCuts: low cost acrylic laser cutting service for small size jobs - [Link]
Jacques VE2EMM writes:
With a maximum capacity of 20 volts and 1 amp, it will supply most of your projects, it’s greatest quality is the protection all your projects, it is capable of limiting the maximum current to as low as 1mA, saving your ICs and transistors in case of an accidental short circuit during the experimenting period of your projects. It is also an excellent battery charger.
Building a workshop Power Supply: 0-20V/0-1A/CC-CV - [Link]
Xerox’s process uses ink containing silver metal that can be used to wire up processing circuitry. It works on surfaces such as plastic that earlier have shown an inconvenient tendency to melt under the high temperature of liquid silver; Xerox’s process works with an ink compound with a much lower temperature, the company said.
The technology uses conventional inkjet printing methods, and though Xerox has used it with conventional desktop printers, the company expects that it would use continuous-feed printers that print on rolls rather than sheets of material. It doesn’t require the super-clean environments needed for conventional silicon chip manufacturing. The Xerox process actually requires printing three layers on a substrate: a semiconductor, a conductor and a dielectric. The silver ink is the layer that conducts electricity.
Xerox develops conductive ink for printable circuits - [Link]
Thermal design can be a more significant determinant of total light output in high-brightness LED designs than the electrical design. LED lifetimes can decrease as temperatures rise, and at high enough temperatures, LED efficacy decreases. To ease the thermal design challenges, National’s new PowerWise® LM3424 LED driver features thermal foldback which reduces regulated current through the LEDs as the temperature increases.
LM3424 Thermal Foldback – Easy Thermal Control for LED Lighting - [Link]
Tired of spending hours and hours in wire soldering? Do your circuits look ugly and you are looking for a way to produce professional-like PCBs? Then you had better try photoetching. And the first step to do that is to have the right equipment that is an Automated Exposure Box. Moreover if you like tinkering with microcontrollers, here is the challenge and it’s high time you launched the design of your own PCB Exposure Box.
Build your Own PCB Exposure Box with countdown timer - [Link]
There are some 89Sxx development board, here is another one. I have designed this single side development board to be used as a tool for learning MCS-51 Microcontrollers, and for easy microcontroller project development.
The 89Sxx development board features :
89Sxx 40-DIL based design, 89S51/52/53
In System Programming (ISP) through the 6-pin header
RS-232 and RS-485 serial port (shared pin) for communicating with serial devices like PC
HD44780 compatible alphanumeric LCD connectivity with backlight control
4 on-board tact switch
16 general purpose IO port pins on 5×2 header (Port0 and Port2)
24Cxx I2C EEPROM
DS1302 serial Real Time Clock (RTC) with battery backup
On-board supply rectifier and voltage regulator
Single sided PCB design
89Sxx Development Board - [Link]
An open-source prototyping shield for Arduino, the ProtoShield kit has tons of cool features to make prototyping on your Arduino easy. With room for small or large breadboards for DIP chips, plus a surface-mount prototyping area too, you’ll be testing all kinds of project ideas in no time.
ProtoShield for Arduino Kit - [Link]
There’s a dark stair well i traverse every night to get to my apartment. I modified a cheap tap-light to be [Tap-> stay on for 40 seconds, then shut off]. The mod takes all of 10 minutes to do, and is really useful if you don’t want to go back and shut it off.
Quick Modification to a Tap Light - [Link]