Another App note from Texas Instruments on op-amp input safety from breakdown voltages during source switch-over. Link here (PDF) Multiplexing is a frequently used technique to perform data acquisition in multichannel systems with minimal signal-chain requirements. In this context, the role of the multiplexer (MUX) in an acquisition system is to switch between channels, and […]
Author Archives: DP
App note: Precision current measurements on high-voltage powersupply rails
Two methods for measuring current and what sense amplifier used are tackled in this app note from Texas Instruments. Link here (PDF) Current is a signal that can provide valuable insight into how a system is operating. Under defined conditions, the amount of current required to perform a task is consistent, making the current information […]
App note: IC temperature sensor accuracy compensation with a PIC microcontroller
This application note is based on the analog output MCP9700/MCP9701 and serial output MCP9800 temperature sensors. Link (PDF) here Microchip Technology Inc. provides a number of analog and serial output Integrated Circuit (IC) temperature sensors. Typically, these sensors are accurate at room temperature within one degree Celsius (±1°C). However, at hot or cold temperature extremes, the […]
App note: Parallel crystal circuit input voltage control
This application note is intended for use with all SMSC LAN products incorporating a parallel crystal circuit. The information contained in this application note provides one option to control the voltage across the input of the crystal circuitry. Link here The designer should incorporate the series resistor shown below in his design to guarantee that the […]
13.8V 5A power supply
Dilshan Jayakody published a new build: 13.8V power supplies are commonly used in armature radio experiments. Most of the portable armature radio transceivers are designed to work with a 13.8V power source. We mainly build this power supply unit to power some of our armature radio circuits and modules. This design is based on the […]
#FreePCB via Twitter to 2 random RTs
Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week: Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch […]
Weather station project
Alvaro Prieto has been working on a wireless weather station project: After playing around with the breakout boards, I decided it was time to integrate it all in a single board. I named it Chaac. This is where I ran into issues with MBED. Making the board support package (BSP) for a custom board was […]
App note: Thermal consideration of flash LEDs
Pulsed LED application like flash LEDs requires adequate thermal management to counter the heavy heat caused by larger current, here’s an app note from OSRAM discussing on thermal management of LEDs. Link here (PDF) This application note focuses on how to develop an adequate thermal management for LEDs in camera flash applications. It provides information […]
App note: Dimming InGaN LEDs
App note from OSRAM on InGaN LEDs dimming method without penalty on its wavelength. Link here (PDF) While the InGaN technology produces the brightest light output across Blue, Deep blue, Verde, True green and White, it is important to understand that the wavelength of the light emitted depends on the forward current. In order to […]
ATtiny13 – 8bit mono class D amplifier
Łukasz Podkalicki shared a how-to on building a Class D amplifier on ATtiny13: I always wonder whether it is possible to make an amplifier of class D on ATtiny13 or not. Some time ago I found George Gardner’s project based on ATtiny85 – TinyD. It was a sign to start challenging it with ATtiny13. It took me […]
Building the ultimate USB power distribution system
Dr. Scott M. Baker published a new build: My goals include: 1. The ability to switch each device on/off with a rocker or toggle switch 2. Current limiting capability via a fuse or similar device 3. Overvoltage protection 4. Visual indicator (LED) of operational status 5. Multiple independent outlet See the full post on his […]
#FreePCB via Twitter to 2 random RTs
Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week: Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch […]
Variable Frequency Drive
Lukas Fässler over at Soldernerd wrote an article detailing his homemade VFD drive for his Schaublin 102 lathe. Check out the video after the break.
Outdoor UV index sensor
A detailed instructions of how to build this outdoor UV index and ambient light sensor from Mare & Gal Electronics: The VEML6075 senses UVA and UVB light and incorporates photodiode, amplifiers, and analog / digital circuits into a single chip using a CMOS process. When the UV sensor is applied, it is able to detect UVA and UVB intensity […]
Semiconductor radioactivity detector – part 2
Robert Gawron has been working on a radioactivity detector, that is available on GitHub: There are many ways to measure radioactivity level, semiconductor detectors sense interactions between ionizing radiation and p-n junction. Because in hobbyist area most popular are Geiger-Muller based detectors (in short: not a semiconductor but lamp based devices), I think it’s a […]
NFC antenna tuning without a VNA
Fred writes: Recently I started work on a new board. This one will be a front door entry system, so I decided to go with something that could read my NFC implant but also had a numeric keypad for the kids (and anyone else) to use. Not everyone wants to be chipped. Crazy, isn’t it? […]
App note: Securing vibration motor leads and wires
App note from Precision Microdrives on how to properly connect wires on to vibration motors for reliability. Link here Vibration motors require electrical power, which must be delivered by wires or PCB tracks to the motor. Precision Microdrives vibrating motors are available in a range of connector forms. From stock, they are available with factory […]
App note: Vibration Motors – Voltage Vs Frequency Vs Amplitude
All about vibration motors and how its frequency and amplitude be controlled in this app note from Precision Microdrives. Link here We’re often asked how to adjust the vibration amplitude or frequency of our various vibration motors. In this article, we’ll look at how simple it is, why it can be useful, and how we […]
An Arduino version of Brooks Shera’s GPSDO
Jeff (aka K6JCA) has a great write-up on implementing the Brooks Shera Phase-Locked Loop GPSDO on an Arduino Platform: This blog post is a continuation of my two earlier GPSDO blog posts. The first one (from a few years back) details a simple Frequency-Locked Loop GPSDO design, based around an Arduino processor. The second (more […]
App note: Ceramic resonators
All about ceramic resonators app note from Abracon. Link here (PDF) Why Ceramic Resonators? Ceramic resonators stand between quartz crystals and LC/RC oscillators in regard to accuracy. They offer low cost and high reliability timing devices with improved start-up time to quartz crystals.