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 […]
Author Archives: DP
DIY thermal imaging
Niklas Roy has written an article detailing his DIY thermal imaging with an IR thermometer: I did not want to hack/destroy the brand new thermometer, as I still plan to use it in its original form later. For that reason, I decided to temporarily attach an old webcam to its back. This way, my laptop can read […]
Teardown, experiments and calibration of an Ist-Rees laser spectrum analyzer
Ist-Rees laser spectrum analyzer teardown from The Signal Path: In this short episode Shahriar takes a close look at an Ist-Rees laser spectrum analyzer. This simple instrument is based on a continuously rotating diffraction mirror to detect various wavelengths. A trigger signal is used to denote the beginning of the scan and the front-panel display shows […]
Muxtronics open source 12V powerbank
A custom 12V powerbank for Cube i7 Stylus from Muxtronics: Why would anyone even try to build a power bank – i.e. an external battery for charging mobile devices – these days? These things are commodity, it’s impossible to compete. Right? Well, that is until you find out that the type of power bank for your […]
TI’s Little Professor
A teardown of TI’s Little Professor vintage calculator from KuzyaTech: This thing was sold for parts and repair since the seller did not think it was working. As it turned out, everything worked just fine, but not in an expected way. This is not your typical calculator, but rather a teaching one. More details at KuzyaTech.com.
Bus Pirate v3.8 free PCB build
Ben built a free Bus Pirate v3.8 PCB. The Bus Pirate is an open source hacker multi-tool that talks to electronic stuff. If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever – we’ll send you a coupon code for the free PCB drawer. Get […]
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: Testing inductors at application frequencies
An app note from Coilcraft on inductance and Q parameters which are the important factors of an inductor and how these values are found. Link here (PDF) The accurate measurement of an inductor has always been more difficult than the measurement of other passive components. The primary difficulty with coil measurements lies in the fact […]
App note: Working voltage ratings applied to inductors
Coilcraft’s application note about why there are no voltage ratings specified on inductors. Link here (PDF) Voltage ratings are often specified for many electronic components, including capacitors, resistors and integrated circuits, but rarely for inductors. This article addresses the reasons why working voltage ratings are not typically published for inductors. There are challenges to determine […]
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 […]
Single tube Lethal Nixie clock
Andrew Moser made a lethal nixie tube clock: Clock 1: Single tube Lethal Nixie clock — you know having all the high voltage lines exposed and un-insulated. Inspiration for this design was from this clock. Unfortunately I built mine right after having surgery. I think the painkillers had something to do with the aesthetics… Anyhow […]
How to make a simple 1 watt audio amplifier (LM386 based)
A tutorial on making an LM386 audio amplifier circuit from Afrotechmods: A tutorial on how to use the popular LM386 class AB audio amplifier IC to build a simple mono 1 watt audio amplifier. It costs less than $3 in parts! There is also a brief discussion of how to use high pass filters to […]
Debugging ARM Cortex-M0+ HardFaults
Erich Styger has written an article on debugging a hard fault on an ARM Cortex-M0+ device: To me, one of the most frustrating things working with ARM Cortex-M cores are the hard fault exceptions. I have lost several hours this week debugging and tracking an instance of a hard fault on an ARM Cortex-M0+ device. More […]
EMP Jammer build
A how-to on making an EMP jammer from JunezRiyaz, project instructables here: An electromagnetic pulse (EMP), also sometimes called a transient electromagnetic disturbance, is a short burst of electromagnetic energy. Such a pulse may occur in the form of a radiated electric or magnetic field or conducted electrical current depending on the source. EMP Jammer is a device […]
SDR radio breathes life into a 75 year old Marconi CR100
Jon Hudson over at DesignSpark writes: This is a belated post of a fun project we did for RS Components. With the upcoming 80th anniversary of the founding of ‘RadioSpares’ – the original name for UK-based RS-Components, and the creation of an “Engineers’ Playground” as a feature of the 2016 Electronica event in Munich, […]
LED traffic light
Domen Ipavec shared his DIY LED traffic light in the project log forum: Traffic lights are all around us, and they seem simple enough but are they really? Real traffic lights can be a very complicated system because it requires sophisticated control and coordination for smooth and safe traffic. The traffic light I made is […]
#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 […]
A 400W (1kW Peak) 100A electronic load using linear MOSFETs
Kerry Wong built a 400W/100A electronic load using linear MOSFETs: I bought a couple of IXYS linear MOSFETs (IXTK90N25L2) a while ago to test their capabilities when used as electronic load, and the result was quite impressive. So I decided to build another electronic load using both MOSFETs. As you can see in the video towards […]
Shirt Pocket Transceiver with the Si5351 and OLED
Pete Juliano’s (N6QW) Shirt Pocket Transceiver with the Si5351 and OLED display: In 2011 I fulfilled a dream of building a shirt pocket sized QRP SSB transceiver. Well actually I built two of them and the second was a diminutive 2″ X 4″ X 2″. Both used through hole components –so no cheating with SMD. […]
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 […]