Teardown & Repair of a SRS DS345 30MHz Synthesized Function Generator

In this episode Shahriar investigates a peculiar problem with a SRS DS345 function generator. The instrument does not appear to produce the correct output signal frequency. After some investigation it becomes clear that a few of the display digits are not active which hide the actual frequency settings. The problem is traced to a broken resistor on the display driver. The schematic of the instrument shows that the resistor is responsible for strobing the affected seven-segment digit. After the repair, the instrument’s performance is verified including the OCXO accuracy.

Teardown & Repair of a SRS DS345 30MHz Synthesized Function Generator – [Link]

Long-fibre carbon nanotubes shown to be carcinogenic

by Thomas Scherer @ elektormagazine.com writes:

Nanotechnology plays an indispensable role in modern materials research and new products. Carbon nanotubes (CNTs) enable production of novel materials with amazing properties. Progress is however not without risk and a recent study on mice has shown that certain types of CNTs have similar carcinogenic properties as asbestos fibers.

Long-fibre carbon nanotubes shown to be carcinogenic – [Link]

Wi-Lamp, the Open Source Wi-Fi LED lamp

LucaBellan @ open-electronics.org discuss about a multi-function LED lamp that is always connected over WiFi.

Since several years already, it is possible to find systems for home automation: irrigation, doors and windows, lighting, air conditioning and alarm systems, everything can be centralized and planned. Recently, the classical control boxes have been replaced by smart systems that are always connected to the Wi-Fi Network and that can be remotely accessed by means of mobile devices such as smartphones or tablets.

Wi-Lamp, the Open Source Wi-Fi LED lamp – [Link]

Biosensors with ECG function for heart rate monitoring in wearables

Graham Prophet @ eedesignnewseurope.com writes:

Silicon Labs has introduced a family of optical biometric sensors providing advanced heart rate monitoring (HRM) by transcutaneous optical measurements, along with electrocardiogram (ECG) capabilities, for a range of wearable fitness and wellness products.

Si117x sensor modules combine ultra-low power, high sensitivity and integration, for smart watches and wrist-based, patch-type and other wearables requiring long battery life and enhanced HRM accuracy. To simplify development and speed time to market, Silicon Labs offers a complete, end-to-end sensing solution featuring the Si117x sensor module, HRM algorithm, Wireless Gecko SoCs for Bluetooth connectivity, and a wrist-based development kit with sample code and example projects.

Biosensors with ECG function for heart rate monitoring in wearables – [Link]

Contactless Controlled Automatic Wardrobe LED Light

Contact-less controlled automatic wardrobe light turns on the LED when you open the wardrobe door. Τhe project is based on Hall effect IC including LED driver and tiny magnet. Board doesn’t require any mechanical switch. When magnet is close to the board, LED is off, when you open the wardrobe door magnet goes far from hall IC and its turn on the LED, the IC also has special features like soft start and soft off. This board can be used in other applications like Automotive Gloves boxes and Storage, task lighting, automotive vanity mirrors. The APS13568 is the heart of the project. The IC can drive LED current up to 150mA. I have set the current 100mA approx. with help of R3. C2 is provided to set the FADE-IN/FADE-OUT time. The value of C2 can be changed as per application requirement.

Contactless Controlled Automatic Wardrobe LED Light – [Link]

Build the World’s Smallest Atomic Clock

Illustration: Emily Cooper

Build the World’s Smallest Atomic Clock, Trap a Nitrogen Atom in a Carbon Cage. By Kyriakos Porfyrakis and Edward A. Laird @ ieee.org:

An atomic clock begins with an oscillator [see diagram], which creates a frequency close to the energy level of the atom being used. If the oscillator deviates from the reference frequency, the atom’s absorption pattern changes, the change is detected by a laser, and the laser’s signal is used as feedback to tune the oscillator. For the very best performance, the atoms must be electromagnetically isolated, which requires equipment that can take up entire rooms.

Build the World’s Smallest Atomic Clock – [Link]

Open Source Ethernet Audio Broadcaster

Luca Pascarella @ open-electronics.org presents how to setup their open source ethernet broadcaster. He writes:

Recently, we have presented an Ethernet audio streaming unit. In particular, we have shown how to configure the boards to work with other similar devices or with VLC Media Player, setting up a point-to-point or a broadcast streaming in all possible configurations. Also in the first episode, we analyzed the electrical circuit and the components choice. Now it is time to describe the board software advanced options and how to update firmware via Internet or manually.

Open Source Ethernet Audio Broadcaster – [Link]

Teardown, Repair & Experiments with an Agilent 8562E 30Hz – 13.2GHz Spectrum Analyzer

Teardown, Repair & Experiments with an Agilent 8562E 30Hz – 13.2GHz Spectrum Analyzer – [Link]

AMSAT MPPT

by Bryce Salmi @ faradayrf.com:

The Radio Amateur Satellite Corporation, AMSAT, recently designated RadFxSat as AO-91 after its successful deployment from a Delta II rocket as a secondary payload to NASA’s JPSS-1. RadFxSat is the first of several AMSAT satellites which are flying a Maximum Power Point Tracker (MPPT) designed and built by Brent and I as a continuation of our Rochester Institute of Technology (RIT) senior design project. The story of the Fox-1 MPPT is a great example of how amateur radio is what you want it to be.

AMSAT MPPT – [Link]

36V, 2-ch, 1.6A synchronous buck LED driver has I²C dimming

Under the “Power by Linear” branding it recently created for the product lines it acquired with its purchase of Linear Technology, Analog Devices has added the LT3964, a dual channel, 36V, high efficiency, synchronous, step-down LED driver with internal 40V, 1.6A power switches and an I2C interface that simplifies LED dimming control.