Category Archives: Tech News


Measuring dielectric constant

Dielectrics are insulators that are used to separate the charged plates in capacitors. The insertion of the dielectric material enhances the charge storing capacity, and hence the capacitance, of the charged plates. Dielectric materials are characterized by what is called dielectric constant, and is defined as the ratio of the capacitance using the material in between the plates, compared to a similar capacitor that has vacuum as its dielectric. Steven Dufresne from Hackaday covers in this tutorial article the basics of dielectric materials and a practical method to measure the dielectric constant using a multimeter. Every now and then you need to

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Nocturnal hypoglycaemia detector

Hypoglycaemia is a condition characterized by an abnormally low level of glucose in blood. It is associated with diabetes, and is likely to occur if someone with diabetes takes too much insulin, eats less than usual, or exercises too hard. Novirium‘s Nighttime Hypoglycaemia monitor is a bluetooth-enabled device that acts as a safety net for type 1 diabetics, while they’re sleeping. The nighttime hypoglycemia results in excessive sweating. This monitor measures the skin temperature and humidity to detect severe nocturnal hypoglycaemic events. Measurements are taken periodically and are sent to a nearby Android phone via Bluetooth. If such an event is detected,

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Filter optimization for A/D conversion

Filters are necessary to eliminate unwanted noise or distortion in a signal prior to any A/D conversion process. Designing a filter to pass the desired frequencies is easy, but it introduces signal loss, or insertion loss. Check out this application note from TI for some useful tips to optimize the filter design to minimize the losses. One of the first steps of filter optimization is the selection of the center frequency and the bandwidth of the filter. Once this step has been completed the task becomes one of putting the filter elements on the printed circuit board (PCB). PCB design is critical to

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CastMinder detects complications in orthopedic casts/splints

Alex Wulff’s CastMinder is a Bluetooth-enabled sensor system designed to predict complications in orthopedic casts and splints. It is capable to detect conditions associated with the onset of complications, including skin infection, skin irritation, bleeding, and something called compartment syndrome, where an excess of pressure can lead to circulation loss in the casted limb. The primary devices in the CastMinder system are tiny sensor nodes embedded inside of a cast or splint. These sensor nodes continuously collect data and dump it via Bluetooth to an iOS application which serves as the brains of the entire network. These small nodes are equipped with a

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Universal motor driver for PIC16F MCUs

This application note from Microchip presents the design of an open-loop speed control TRIAC-driven universal motor driver board. An interesting thing about this design is it uses Core Independent Peripheral (CIP) on an 8-bit microcontroller to optimize the processing speed and free up the CPU usage. The complete source code and reference design material are included. The universal motor used in this application note runs from 120V-240V AC power and is driven from a TRIAC. A bench test for running a 220V universal motor has been done. The circuit is powered off the line from an non-isolated AC supply; therefore, safety precautions should be taken when working with this type of system. An isolated on-board UART

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