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, […]
“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 […]
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 […]
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 […]
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 […]
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 […]
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 […]
Part 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 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 […]
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 […]
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 […]