Immersion Heaters and Potential Fire Risks

Immersion heater terminal box. © Eugene Brennan

So I was doing some gardening for the sister today and she mentioned a smell that was coming from her immersion, which immediately rang alarm bells in my engineering head, knowing what was likely. So I investigated.

My Telemetry Software Didn't Control Voyager 1

Credit: NASA/JPL-Caltech

NASA's decision to switch off an instrument on Voyager 1 to keep the spacecraft operating reminded me of my much less glamorous work in a past life, when I wrote telemetry software to control pumps and other equipment in sewage and water treatment plants.. But they were only down the road from Dublin in Kildare, Laois and other places throughout the country. If the remote software didn't work, or crashed, often due to frustratingly annoying transient bugs, usually a watchdog circuit kicked in to reboot the SCADA system (Supervisory Control and Data Acquisition). If there was a big problem and frequent crashes or anomalies, technicians would reinstall software. Eventually, I added the facility to upload new versions of software. All this was much less sophisticated than the complex software that runs on computers nowadays. Voyager 1 is nearly a light day away meaning a radio signal takes nearly a day to reach the spacecraft. Not much hope of sending people out to do an upgrade. Perhaps they can upload new code.

 

Edit: Yes, they can upload new "patches" and code updates. Code is restricted to around 64k. Voyager 1 has six computers, three of which are backups. The data bus is 16 to 18 bits wide and the address bus is 12 bits wide.

How Can Insects Survive Falling From a Height?

Forces on a falling insect. © Eugene Brennan

One of the reasons insects don't hurt themselves when they fall is because they have a low terminal velocity and are travelling relatively slowly when they reach the ground. Terminal velocity is the maximum velocity attained by a falling body in a fluid such as air or water and subject to a force called drag, (resistance to motion). For humans, it's around 120 mph or 54 m/s lying flat. For an insect, it's typically around 2 m/s. Once the increasing drag force balances the weight (another force), there's no net force and an object stops accelerating (Newton's second law of motion). Also when an insect hits the ground, because it has such a small mass, the g-force on its body is small because it has to shed so little momentum, and that also helps prevents damage. So it's a combination of low terminal velocity, small mass and also having an outer protective layer or exoskeleton that gives them protection.

Learn How to Solder: A Complete Guide for Beginners

Image by permission Weller Tools

A Basic Skill When Building Electronic Circuits

Soldering is a fundamental skill essential to learn when building electronic circuits or fixing circuit boards.

Kippure TV Mast Visible From Kilcullen

Kippure in the Wicklow Mountains, photographed from Kilcullen. © Eugene Brennan

I took this with my 10-year-old Nikon D5300 SLR from St. Brigid's Well on Saturday evening. The second photo below is a crop of the 6000-pixel-wide image. If you have good eyesight, you can see the 127-metre-tall television transmission mast on Kippure on a clear day. It's approximately 7 m taller than the Spire in O'Connell Street in Dublin and located 17.5 miles away from Kilcullen as the crow flies. (I can just about make it out with the naked eye). At night of course it's very noticeable, and the beacons on the mast can be seen flashing in the distance. They used to be red, but they changed them to white at some stage. I've seen the flashing from as far away as Kilmeague.

I haven't figured out why this camera always takes such dull photos. I reckon smartphones must boost the colour saturation, highlights and contrast in images to make them more vivid. I have the setting for this (can't remember what it's called) set as "neutral" in the camera so that images aren't altered. I can always change the settings later during post processing.

Edit: An FB photography group I'm a member of confirms that this is the case and images are flat if neutral photo style is selected. Saving photos as JPGs compresses images and reduces filesize, so I'm going to retake the photo and save as raw to see whether it makes much of a difference as regards detail and artefacts.

The TV mast on Kippure (a crop from the image above) © Eugene Brennan

 

Why Is Most of an Iceberg Under Water? And How Much?

Original uncaptioned image Lurens, public domain image via Pixabay.com

Ninety Percent of an Iceberg Is Below the Waterline

Icebergs can be massive, but did you know that you're only seeing literally the tip of them above the water? Yes, up to 90% of an iceberg's volume can be under water. But why does that amount sink and not just float above sea level like the rest of it? In this article we explore why.

What's the Difference Between Analogue and Digital?

© Eugene Brennan

Analogue vs. Digital

We often hear about analogue and digital in the context of communications, sound recording, cameras, TV, radio, and electronic devices. But what exactly is the difference, and is digital better than analogue? Why has digital replaced analogue in audio, digital imaging, and electronic communication?

Vodafone Internet Service Down After Thunderstorm

 

The Internet was dropping intermittently since the thunderstorm the other night. A Vodafone technician replaced the modem yesterday afternoon, but still no go. Then the service disappeared completely when the technician was still working on it.

Why Is Binary Used in Electronics and Computers?

Why is binary used in electronics? Geralt via Pixabay.com

Why Do Computers Use Binary?

The binary numbering system is the basis for the storage, transfer and manipulation of data in computer systems and digital electronic devices. This system uses base 2 rather than base 10, which is what we are familiar with for counting in everyday life.

How to Convert Decimal to Binary and Binary to Decimal

Binary number and its decimal equivalent. © Eugene Brennan

Base 2, the Basis for Binary Code

The base 2, or binary numbering system is the basis for all binary code and data storage in computing systems and electronic devices. This guide shows you how to convert from binary to decimal and decimal to binary.