Archive for the ‘Sensors’ Category

MicroHTR (Part 9)

Part 1, 2, 3, 4, 5, 6, 7, 8, 9 Here is an update of the MicroHTR (aka micro heater application) topic. Guy is a former marine pilot and his hobby is flying his touring-motor-glider wrote to me a very interesting message: “When flying close to cloudbase, the air becomes cold and the relative humidity […]

Light sensor (Part 2)

Part 1, 2 In the previous part of this publication, I covered the subject of sensitivity. As for many sensor, the range is very broad and a simple configuration cannot help covering the whole range of light intensities. As in the dated controllers, we might want to use a hand operated sensitivity selector. Although this […]

Light sensor (Part 1)

Part 1, 2 Sensing light is probably one of the most common sensing and probably one of the simplest measurement to start with. Light sensors are used to detect light or brightness in a manner similar to the human eye. They are most commonly found in industrial lighting, consumer electronics, and automotive systems, where they […]

TASCAM Sound Recorder (Part 5)

Part 1, 2, 3, 4, 5 As a professional equipment, the TASCAM DR40-X recorder features XLR inputs. These are in fact combo inputs which are compatible with standard XLR connectors and 6.35 mm jack connectors . More important than the hardware, the electronics behind the connectors are very important. Most audio devices rely on unbalanced […]

3D prints: Stevenson screen

Building a basic weather station today is simple and cheap thanks to specialized integrated circuits featuring temperature, humidity and pressure sensing. Up to now my favorite is the Bosh bme280; you may easily find it ready for use on small PCBs, easy to connect on any prototyping platform. Adafruit industries is selling a very convenient […]

3D Printing (Part 14)

Part 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 The heating plate is made of two symmetric printed conductive layers ~1.5 Ohm each. As printed on the heating plate you may wire them for use with 12 V or 24 V power supplies. As we need to add an extra power supply the choice for a 24 V power supply […]

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 […]