App note from Vishay about tight tolerances that sense resistor requires for accurate and efficient Li-ion battery chargers. Link here (PDF) Intelligent Li-ion rechargeable batteries utilize current sensing resistors with ultra low ohm, low TCR, tight tolerance, high withstanding surge current and low thermal EMF.
Author Archives: DP
App note: Grid resistors: Determining nominal resistance
App note from Vishay on selecting grid resistors base on their application as resistors vary over continuous duty. Link here (PDF) Nearly all resistor materials change resistance as temperature increases. Depending on the material, this change can range from a few percent to 50 % and higher at 100 % duty on the resistor (100 […]
Control your Arduino over the Internet using Blynk
John Boxall from Tronixstuff has written an article on using Blynk with Arduino: There are many ways of remotely-controlling your Arduino or compatible hardware over the Internet. Some are more complex than others, which can be a good thing or a bad thing depending on your level of expertise. Lately we’ve become more interested in this topic […]
Generating PWM signals
KF5OBS writes, “In this video I’m showing how to generate a PWM signal that’s behaving proportionally to analog control signal.” Details at KF5OBS’ blog.
Free PCB coupon via Facebook to 2 random commenters
Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three […]
Rediscovering the magic of wireless communication
Ashish Derhgawen’s article on rediscovering the magic of wireless communication: In this article, I will tell you the story behind one of the most important technological inventions of modern times – wireless communication. I will also describe some of my own experiments with high voltage spark transmitters and coherers! But before I talk about those, […]
Merry Christmas!
Merry Christmas and Happy Holidays to all. May you find many PCBs and other electronics wizardry under your tree or pole. Remember, support is available on Christmas. Just give us a shout in the forum.
Paint Machine, a printer that prints small bitmaps on the street
Alex Weber has posted a new project on building a DIY Paint Machine, he writes: Here is my latest creature, the Paint Machine. It’s a machine the prints simple bitmaps with spray chalk on the street or sidewalk. For a large-scale project like a home exterior painting Edmonton, it is advised that you hire a professional painting […]
Tutorial on the theory, design and characterization of a CMOS transimpedance amplifier
Tutorial on the theory, design and characterization of a CMOS transimpedance amplifier from The Signal Path: In this episode, Shahriar and Shayan discuss the design and characterization of a deceptively simple CMOS inverter-based transimpedance amplifier. The the large and small signal behavior of the CMOS inverter is discussed and measured using the Keithley 2450 and […]
C64/SX64 RAM Cartridge (SD2IEC part)
Sjaak designed and built a C64 RAM/ROM cartridge, which has a 6264 SRAM chip and an Atmel 644. He did program an Atmega with a Bus Pirate: Today came in the Atmega644P’s in TQFP package I scored on eBay. Today I’m focusing on the SD2IEC part of the RAM cartridge. I was a bit scary to order […]
#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 […]
CC2538 development board
Jelmer Tiete designed and built a development board for the TI CC2538, that is available at GitHub: It’s a nice little system-on-chip with an ARM Cortex M3, 2.4 GHz 802.15.4 radio and it runs at 32 MHz. Perfect for all your favorite Internet Of Things (IOT) shenanigans. Contiki supports this chip pretty well, which means […]
74181 ALU design on Altera MAX II CPLD
Dilshan Jayakody writes: 74181 is 4-bit arithmetic and logic unit introduced by Texas Instruments in March 1970 and it is known for being the first ALU in single package. This chip is no longer in manufacturing but still it is quite popular in CA (computer architecture) courses in many colleges. To test the behavior of […]
Apple II ROM Dumper
Quinn Dunki created an Apple II ROM tool project and posted a great write-up on digging into the ROM of her Apple IIc Plus: You may recall way back when I started my Apple II ROM Tool project, that I had intended to fix some bugs. That was the whole point of this adventure. It […]
App note: A microwatt charge pump boosts 1 V to 1.8 V at 90% efficiency, providing “Always On” standby power for microcontrollers
Silicon Labs’ app note featuring low power boost for microcontrollers. Link here (PDF) Boosting the output voltage of common alkaline button-cells to at least 1.8 V needed by microcontrollers provides an “always on” standby power source sufficient for low-power oscillator interrupt/sleep state operation. Two ultralow power op amps are used in a charge pump configuration […]
Free PCB Sunday: Pick your PCB
We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will […]
App note: How to generate a negative voltage using buck converters?
An app note from Alpha and Omega Semiconductor on using their AOZ1016 buck regulator to generate negative voltage. Link here (PDF) The negative voltage source is widely used in various applications such as computing systems, LCD panels, audio amplifiers, etc. Using the additional secondary winding of a transformer is the widely used approach to generate […]
App note: Latency in factory automation
An app note (PDF!) from Texas Instruments on importance of latency in factory automation: Latency is a critical parameter in Ethernet networks developed for Factory Automation applications. Latency is not a defined value for Ethernet as specified by the IEEE 802.3 standard. Nor is Ethernet inherently synchronous or repeatable. This disconnect between the inherent characteristics of Ethernet and the needs […]
App note: Switch Mode Power Supply (SMPS) Topologies (part I)
Here is an app note (PDF!) from Microchip describing the basics of different SMPS topologies: The industry drive toward smaller, lighter and more efficient electronics has led to the development of the Switch Mode Power Supply (SMPS). There are several topologies commonly used to implement SMPS. This application note, which is the first of a […]
Lab LED constant current controller board
Ladvien blogged about his Lab LED constant current controller board project he made using DirtyBoard PCBs: A little lab controller PCB I’m working on. It centers around four high-power constant current circuits meant to be driven by an Atmega328’s PWM. I hate working on anything mechanical in dim light; comes from dropping parts down under […]