Wireless Nixie Thermometer

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by christian.ich.7 @ instructables.com:

The Target of this Project was to learn how to use different functions of the atmega:

• Connecting two Atmegas with a wireless connection
• Each Atmega has a Thermometer (DS1621) to read the actual temperature
• Use the sleep Mode of an Atmega
• Controlling a Nixie bargraph In-13

Wireless Nixie Thermometer – [Link]

Arduino Chess Clock

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by benhur.goncalves @ instructables.com:

Hey folks! After making an Arduino smartwatch just last week, I received many complaints,or tips, to use a RTC (real-time clock) module. That’s because the Arduino timer is not very precise, it can lose a couple a minutes along a full work day. Luckly, I had one of those modules at my home, I decided to give it a try. However, I faced some challenges along the way, as I can show you here.

Arduino Chess Clock – [Link]

RELATED POSTS

Design & simulate in the clouds

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by Michael Dunn @ edn.com:

It was a few years ago that I first heard of a free site where you could draw and simulate designs. “What’s the point?” I thought. But, the idea is taking off. Was I wrong?

I questioned the usefulness of this cloud concept because there had already long existed good, free circuit simulators. A quick download, and off you go, drawing and simulating. Why deal with the extra vagaries of service-provider availability, and of course, Internet access?

Well, as with any other cloud-based service, there are advantages, such as being able to work anywhere, on any supported device, and not having to deal with the software directly. And while the services out there now seem mostly suited to exploration, hobby, and simple prototype use, they will keep getting better. Some are arguably already professional grade.

Design & simulate in the clouds – [Link]

Supercap energy density rivals batteries

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by Martin Cooke @ elektormagazine.com:

A novel design of supercapacitor using a hybrid silica sol-gel material and self-assembled monolayers of a common fatty acid has been developed by researchers working at the Georgia Institute of Technology. The device is said to provide an electrical energy storage capacity rivaling certain batteries, with both a high energy density and high power density.

The new material is composed of a silica sol-gel thin film containing polar groups linked to the silicon atoms and a nanoscale self-assembled monolayer of an octylphosphonic acid, which provides the insulating properties. The bilayer structure blocks the injection of electrons into the sol-gel material, providing low leakage current, high breakdown strength and high energy extraction efficiency.

Supercap energy density rivals batteries – [Link]

Teardown, Repair & Analysis of a Rohde & Schwarz FSH3 3.0GHz Portable Spectrum Analyzer

In this episode Shahriar examines a faulty R&S FSH3 100kHz – 3.0GHz Portable Spectrum Analyzer. This exceptionally dirty unit does not power on and is missing a power supply and battery. After verifying the correct operation of the battery charger circuit and keypad the problem is traces to a damaged SOT-23-6 MOSFET device which is part of a fly-back DC-DC converter. A replacement MOSFET with a lower current rating proves to be a failure as the device fails on startup. A higher rated MOSFET resolves the problem and device begins to operate correctly.
The block diagram of the system as well as a detailed block diagram of the RF section is presented and correlated with the teardown of the RF section. The super-heterodyne down-conversion circuits and components are examined.

Teardown, Repair & Analysis of a Rohde & Schwarz FSH3 3.0GHz Portable Spectrum Analyzer – [Link]

EEVblog #777 – Keithley 177 Microvolt DMM Repair

Come on a ride as Dave repairs an intermittent Keithley 177 Microvolt DMM, garden paths and all.

EEVblog #777 – Keithley 177 Microvolt DMM Repair – [Link]

Visualizing RF Standing Waves on Transmission Lines

This video illustrates how RF (radio frequency) standing waves are created in transmission lines – through the addition of the forward (transmitted) wave and the reflected wave that results from improperly terminating the line or matching the load or antenna to the transmission line impedance. I have done several videos that relate to transmission lines, terminations and reflections – all of which tell a piece of the story. This video is another piece, and I hope it helps you to understand how standing waves are formed and what the “look” like.

Visualizing RF Standing Waves on Transmission Lines – [Link]

Arduino DDS AD9850 Antenna Analyzer

This is a no frills DIY Analyzer intended for frequencies ranging from 1.6 to 30 Mhz. This simple Antenna Analyzer could be a nice project for anyone just getting started in setting up a station on the HF bands.

Arduino DDS AD9850 Antenna Analyzer – [Link]

RELATED POSTS

WiFi smoke detector

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by Proto G @ instructables.com:

This is a simple WiFI Smoke Detector that texts me when it senses smoke. I made this for my battery storage area in case of a lithium polymer fire. I still have all of my regular smoke detectors installed and I don’t suggest relying only on this, but rather as an extra layer of protection. If I had a house I would install a proper fire alarm system that calls the fire department, but I live in a small apartment so I can’t. I can set this one to email and call the local fire department as well(local laws apply). In my county it is allowed as long as you register it with the fire department. Either way, I would rather call the fire department myself when I receive multiple texts.

WiFi smoke detector – [Link]

Build a Motion Control Rig for Time-Lapse Photography

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by Tyler Winegarner and Chris Bordeleau @ makezine.com:

If you dig around in your camera’s settings long enough, you’re almost assured to find that it has a mode to create time-lapse videos — those magical, time compressing movies that can turn any hillside or street corner into a lightning-paced dreamscape.

Time-lapse videos by themselves are easy enough to make, but if you do enough of them, you’re likely to get bored with the motionless camera framing. But what can you do here? Having a moving time lapse means moving a camera very predictably, and very, very slowly. You can build a simple panning rig out of a mechanical kitchen timer, but that’s only good if your time lapse is an hour or less, plus, the camera will rotate the full 360 degrees in that hour, further limiting your control.

Build a Motion Control Rig for Time-Lapse Photography – [Link]