An auto-ranging nanoAmp meter from LowPowerLab: CurrentRanger is a nanoAmp current meter featuring auto-ranging, uni/bi-directional modes, bluetooth data logging options and more. It is a highly hackable and affordable ultra low-burden-voltage ammeter, appropriate for hobby and professional use where capturing fast current transients and measurement precision are important. More details on LowPowerLab site. Check out […]
Author Archives: DP
Teardown of an Array 3711A 300W DC electronic load
Kerry Wong did a teardown of an Array 3711A 300W electronic load: I have made many electronic loads in the past. For instance this simple harddrive cooler housed small dummy load, this more sophisticated constant current/constant programmable load and this heavy-duty electronic load that is capable of sinking over 1kW under peak load. In this […]
#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 […]
Simple homebrew 6502 computer
Sven Krasser blogged about his 6502-based homebrew 8-bit computer build: After completing my VGA Generator project a while back, I’ve embarked on a new electronics project: building a simple 6502-based homebrew 8-bit computer on a breadboard. There are a bunch of similar projects online from which to draw ideas. Some projects set constraints such as only […]
Making an e-Paper Etch-a-Sketch
Scott Baker has been working on making an Etch-a-Sketch using modern e-Paper displays and optical encoders: Above you can see my prototype. I’m using a 4.2″ e-Paper display from Gooddisplay, together with the Waveshare breakout board. I have a couple of ENS1J-B28-R00128 optical encoders that I attained on eBay. I specifically chose these encoders instead […]
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: Blood pressure monitor fundamentals and design
Application note from NXP on blood pressure monitor fundamentals using their medical oriented MCUs. Link here (PDF) Arterial pressure is defined as the hydrostatic pressure exerted by the blood over the arteries as a result of the heart left ventricle contraction. Systolic arterial pressure is the higher blood pressure reached by the arteries during systole […]
App note: How to eliminate over stress of MOSFET during start-up of flyback converter
App note from Richtek about their embedded soft-start function to eliminate MOSFET stress. Link here Switching Power Supply, compared to Linear Power Supply, is widely used due to its advantages, such as small size, light weight, high efficiency, etc. Flyback Converter, one of the switching power supply topologies, is most suitable for power supply systems […]
Grbl_ESP32 development board version 3.1
A board to control your CNC machine with Grbl_ESP32 designed by Bart Dring, that is available on GitHub: This is a Grbl_ESP32 CNC Development board. This is a quick and easy way to use and test CNC on the ESP32 controller. Grbl is a great CNC firmware that has been around for nearly a decade. […]
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 […]
A simple 8-channel receiver voting controller for enhanced repeater coverage and usability
KA7OEI has written an article detailing a simple 8-channel receiver voting controller: To simplify things, this voting controller sits in “front” of an ordinary repeater controller, taking the audio and COS inputs from the various receivers and outputting a single audio and COS signal. If the repeater system in question uses subaudible tones, it is […]
trigBoard – Ultra low power ESP8266 IoT platform
Kevin Darrah writes: The trigBoard is an IoT project that does one thing – it pushes you a notification triggered by a digital input. Well, it’s much more than that, but this is the inspiration. I wanted to design a WiFi board that essentially sleeps most of its life, but when that door switch, flood […]
#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 […]
SAMD21 LoRa development board with GPS
Michael Krumpus designed and built a SAMD21 development board with LoRa radio module and GPS receiver, that is available on GitHub: I’ve been doing some LoRa projects lately in order to learn as much as I can about this exciting new radio technology (see this LoRa mesh networking project and this LoRa weather station). ATmega328-based […]
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: Common mode filter inductor analysis
App note from Coilcraft on the design and construction of common mode filter inductor. Link here (PDF) Noise limits set by regulatory agencies make solutions to common mode EMI a necessary consideration in the manufacture and use of electronic equipment. Common mode filters are generally relied upon to suppress line conducted common mode interference. When […]
App note: How current and power relates to losses and temperature rise on inductors and transformers
Coilcraft’s app note on temperature rise due to losses on inductors and transformers. Link here (PDF) Core and winding losses in inductors and transformers cause a temperature rise whenever current flows through a winding. These losses are limited either by the allowed total loss for the application (power budget) or the maximum allowable temperature rise. […]
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 […]
N6QW Heathkit SSB transceiver
Pete Juliano, N6QW, has a nice build log on his newest version Heathkit 40M SSB Transceiver: What are you thinking — I am not trying to break any world record? My XYL asked me that question today — why are you building another rig? Followed up by a snide comment that I had so many […]
Relays (DC): 99.9% less power and latching option
Technovative writes, “The purpose of this article, is to show a simple method to increase the power efficiency, and functionality, of standard DC actuated electromagnetic relay switches.” Project instructables here.