Design & simulate in the clouds


by Michael Dunn @

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


by Martin Cooke @

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]


WiFi smoke detector


by Proto G @

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


by Tyler Winegarner and Chris Bordeleau @

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]

WXR3031 rework station will replace you three devices


Soldering, deslodering, hot-air works but also a record of your work in a PC – this is the Weller WXR 3031.

Good soldering station is usually a fundament of a workplace. Desoldering station is usually a necessity if you work in development or service. And a hot-air station? – this one is becoming a must at any development or rework of PCBs with SMT components. If we already know, that it´s ideal to have all these three device on a workbench, couldn´t they be integrated into one device?

The answer can be Weller WXR 3031

Right at the beginning it can be said, that in this case a connection into one station brings real benefits, rather than well-known negatives of various „3in1“, „7in1“ and similar products and agents :-).

Perhaps the biggest benefit is saving of space on a workbench and the same control interface for all tools. If you´re familiar with Weller WX2 stations, which we introduced to you in our articles, then you know, that they belong to a very top segment. If we “add” to them a section for a hot air, as well as other additional features and a possibility to connect a vacuum pickup, we receive a top class device which makes every electrician happy.

  • 3 channels
  • 420 (600W) total power
  • temperature 100-450 (550) °C/ 200-850°C (hot-air part)

Available are 4 soldering tools (from micro up to powerful 200W) and 3 tools for desoldering. Concretely WXR 3031 set contains:

  • WXR3 unit
  • hot-air tool WXHAP
  • desoldering tool WXDP 120
  • soldering tool WXP 120

A big benefit for professional workplaces is also a possibility to record your work (traceability – temperature profile) over the USB port to a PC. USB port also serves for a possible firmware update. WXR3031 features intelligent identification of a connected tool and a parameter memory built-in in a given tool, intelligent power save function and a possibility to control several additional devices via the WX port.

WX series meets all requirements for demanding and precise everyday work. High power, user comfort and a wide range of soldering tools and tips will be probably beneficial even for your workplace.

Possibilities of the WXR3031 are very wide and perhaps best illustrated in the attached video. Detailed information will provide you the WXR3031 datasheet , user manual WXR3031 and the “WXR3 Quick start”.
WXR 3031 station was incorporated into our standard stock offer.

WXR3031 rework station will replace you three devices – [Link]

Terahertz Optical Transistors Beat Silicon


by R. Colin Johnson @

PORTLAND, Ore.–Purdue University researchers have demonstrated a CMOS-compatible all-optical transistor capable of 4THz speeds, potentially over a 1000 times faster than silicon transistors.

Nano-photonic transistors processed at low-temperatures can be fabricated atop complementary metal oxide semiconductors (CMOS) to boost switching time by ~5,000-times less than 300 femtoseconds (fs) or almost 4 terahertz (THz), according to researchers at Purdue University. The aluminum-doped zinc oxide (AZO) material from which these optical transistors are fabricated has a tunable dielectric permittivity compatible with all telecommunications infrared (IR) standards.

Terahertz Optical Transistors Beat Silicon – [Link]