Posts Tagged ‘Electronics’

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 […]

Direct Digital Synthesizer (DDS) (Part 7)

Part 1, 2, 3, 4, 5, 6, 7, 8, 9 A recent project lead me to excavate a quite old DDS design which may be of some interest for you. Instead of using a ladder of resistors, this design features a simple, cheap and yet powerful digital to analog converter. I will later explain why I choose this particular Microchip circuit but for […]

PLD (Part 5)

Part 1, 2, 3, 4, 5, 6 HL2 PLD may be used for safety applications too. In this configuration, the PLD is able to detect movements up to 7 m away within and almost 90° view angle. It features a PIR (Passive Infra Red) sensor from Panasonic. This sensors is available in different sizes depending on the required range; the enclosures […]

3D Printing (Part 12)

Part 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 3D printing can be tiring for the nerves… For a week or so, I was enable to print full size parts without enduring severe problems such as splitting layers, irregular faces and even gaps. Here is an illustration of the prints before the fix (on top) and after the fix. The first layers […]

PLD (Part 4)

Part 1, 2, 3, 4, 5, 6 Using the HL2 PLD (Place and Leave Device) is easy and usefull. We ran the earliest tests on… soil moisture. The reason why we chose this one is that I have always liked to have a green plant in my office and this one might last longer than the others. Because it is fitted […]

PLD (Part 3)

Part 1, 2, 3, 4, 5, 6 The name PLD stands for “Place and Leave Device”. The original design is big enough to encapsulate its power reserve, the radio module, an arduino ™ microcontroller which will run your own code, and connectors for programming, debugging or plugging sensors. The radio module features the HL2 stack which handles data in terms of […]