Archive for the ‘Electronics’ Category

PCBs (Part 2)

Part 1, 2 Let’s exercise the tip and tricks that I shared with you in my latest post. Here are the requirements for this subject: Project: As a one idea per minute person, it was hard for me to stick to one project and one design. However, I had in mind the project of building […]

PCBs (Part 1)

Part 1, 2 PCB design pitfalls… A quick glance on the net brought me to various interesting web sites: “4 Circuit Board Design Mistakes to Avoid” “PCB Design – The Top 5 Mistakes” “6 PCB Design Mistakes to avoid designing printed circuit boards” “7 Fatal Mistakes to Avoid on Your PCB Design” “Top 9 mistakes […]

Current generators (Part 1)

Part 1 Here starts a new series of post dedicated to current generators. As usual, the idea is to describe working experimental prototypes that feature few components and quite good performances. Current generators can be found in various applications such as battery chargers (advanced ones, aka multiple stages or intelligent battery chargers), LED drivers and […]

Particle sensors (Part 1)

Part 1 I am amazed by the massive improvements of sensors along the last 10 years. Not so long ago, some sensors would fit in a shoe box and require 24 VDC, not to talk about the interfaces, weight, etc. These improvements are mainly due to the incorporation of advanced sensors in smart phones: camera, […]

Metal detector (Part 1)

“Dear cousin, I lost my keys in the middle of the meadows, would you please make a metal detector for me ? Urgent !“ This is really how this project started ! More or less, as I have in mind the design of an Earth’s Field Nuclear Magnetic Resonance spectrometer which features magnetic fields sensors on […]

Switch Mode Power Supplies (Part 3)

Part 1, 2, 3 Current sensing. This part is probably the most critical and most uneasy. It is critical because current sensing will protect both the power supply and the driven load from excessive currents and thus excessive amounts of energy dissipated in both the source and the receiver. There are multiple designs available for […]

Direct Digital Synthesizer (DDS) (Part 9)

Part 1, 2, 3, 4, 5, 6, 7, 8, 9 Let’s go a few steps further in the direction of a fully featured arbitrary wave generator ! The early posts describe how to generate clean waves at various frequencies. In this post, I will explain how to offset the signal and how to attenuate it. Setting negative offsets requires… negative voltage ! Which Arduino  platforms do […]

Switch Mode Power Supplies (Part 2)

Part 1, 2, 3 Next picture illustrates the principle of operation of my proposal for an arduino controlled Switch-Mode Power Supply (SMPS): Instead of using an integrated chip, we will use arduino as a controller. The basic configuration requires an output line to drive the switch and two analog inputs for reading the voltage from the current […]

Memories from my first trips in Silicon Valley

As I was tidying my electronic components, I found an untouched plastic bag containing an DC that I bought a loooooooong time ago in San Jose. At this time, some friendly colleagues from SID (HP Scientific Instruments Division located in California Avenue) drove me to some great places around Palo Alto, including some electronic shops […]

Switch Mode Power Supplies (Part 1)

Part 1, 2, 3 This is the begining of a series of posts dedicated to an original subject that I had in mind for sometimes now. After few attemps, I decided to share my early design which might drive us up to building a versatile lead-acid battery charger. The aim of these posts is not […]