Amidst the discussions about grid-level energy storage solutions, it is often easy to forget that energy storage can be done on the level of a single house or building as well. The advantages here are that no grid management is needed, with the storage (electrical, thermal, etc.) absorbing the energy as it becomes available, and discharging it when requested. This simplifies the scale of the problem and thus the associated costs significantly.
Perhaps the most common examples of such systems are solar thermal collectors with an associated hot water storage tank, and of course batteries. More recently, the idea of using a battery electric vehicle (BEV, ‘electric car’) as part of a home storage solution is also gaining traction, especially for emergencies where the grid connection has failed due to a storm or similar emergencies. But all-in-all, we don’t see many options for home-level energy storage.
When looking at integrating a photovoltaic solar panel into a project, the naive assumption would be that you simply point the panel into the general direction of where the Sun is, and out comes gobs of clean DC power, ready to be used for charging a battery. To a certain extent this assumption is correct, but feeding a solar panel’s output into something like a regular old PWM buck or boost regulator is unlikely to get you anywhere close to the panel’s full specifications.
The keywords here are ‘maximum power point’ (MPP), which refers to the optimal point on the solar panel’s I-V curve. This is a property that’s important not only with photovoltaics, but also with wind turbines and other highly variable power sources. The tracking of this maximum power point is what is generally referred to as ‘MPPT‘, but within this one acronym many different algorithms are covered, each with its own advantages and disadvantages. In this article we’ll take a look at what these MPPT algorithms are, and when you would want to pick a particular one.
[Marek] has an impressive collection of old Soviet-style Geiger counters. These are handy tools to have in some specific situations, but for most of us they would be curiosities. Even so, they need some help from the modern world to work well, and [Marek] has come up with some pretty creative ways of bringing them into the 21st century. This version, for example, adds WiFi capabilities.
This build is based on the STS-5 Geiger tube but the real heavy lifting is handled by an ESP8266 which also provides a wireless network connection. There are some limitations to using an ESP8266 to control a time-sensitive device like a Geiger tube, especially the lack of local storage, but [Marek] solves this problem by including a real-time clock and locally caching data until a network connection is re-established. Future plans for the device include adding temperature and atmospheric temperature sensors.
Eventually this Geiger counter will be installed in a watertight enclosure outside so [Marek] can keep an eye on the background radiation of his neighborhood. Previously he was doing this with another build, but that one only had access to the network over an Ethernet cable, so this one is quite an upgrade.
When it comes to an engineering marvel like the James Webb Space Telescope, the technology involved is so specialized that there’s precious little the average person can truly relate to. We’re talking about an infrared observatory that cost $10 billion to build and operates at a temperature of 50 K (−223 °C; −370 °F), 1.5 million kilometers (930,000 mi) from Earth — you wouldn’t exactly expect it to share any parts with your run-of-the-mill laptop.
But it would be a lot easier for the public to understand if it did. So it’s really no surprise that this week we saw several tech sites running headlines about the “tiny solid state drive” inside the James Webb Space Telescope. They marveled at the observatory’s ability to deliver such incredible images with only 68 gigabytes of onboard storage, a figure below what you’d expect to see on a mid-tier smartphone these days. Focusing on the solid state drive (SSD) and its relatively meager capacity gave these articles a touchstone that was easy to grasp by a mainstream audience. Even if it was a flawed comparison, readers came away with a fun fact for the water cooler — “My computer’s got a bigger drive than the James Webb.”
Of course, we know that NASA didn’t hit up eBay for an outdated Samsung EVO SSD to slap into their next-generation space observatory. The reality is that the solid state drive, known officially as the Solid State Recorder (SSR), was custom built to meet the exact requirements of the JWST’s mission; just like every other component on the spacecraft. Likewise, its somewhat unusual 68 GB capacity isn’t just some arbitrary number, it was precisely calculated given the needs of the scientific instruments onboard.
With so much buzz about the James Webb Space Telescope’s storage capacity, or lack thereof, in the news, it seemed like an excellent time to dive a bit deeper into this particular subsystem of the observatory. How is the SSR utilized, how did engineers land on that specific capacity, and how does its design compare to previous space telescopes such as the Hubble?
Over the years we’ve covered many projects aimed at detecting elevated radiation levels, and a fair number of them have been Internet connected in some way. But as they are often built around the Soviet-era SBM-20 Geiger–Müller tube, these devices have generally adhered to a fairly conservative design. With the current situation in Europe heightening concerns over potential radiation exposure, [g3gg0] thought it was a good a time as any to revisit the idea of an Internet-connected Geiger counter using more modern components.
Now to be clear, even this modernized approach still makes use of that same SBM-20 tube. There’s such an incredible wealth of information floating around out there about how to work with them that you’d almost put yourself at a disadvantage to chose something else to base your design on. Put simply, it’s hard to go wrong with a classic.
An unfortunate bug was discovered in the HV circuit.
That said, [g3gg0] decided early on that the design would use as many SMD components as possible, a considerable departure from many of the SBM-20 counters we’ve seen. That meant coming up with a new high-voltage power supply capable of providing the tube with the necessary 400 V, which from the sound of things, took a few attempts to complete. The final result is perhaps the smallest and cleanest looking board we’ve ever seen play host to this particular tube.
To run the show, [g3gg0] selected the ESP32-PICO-D4. You certainly don’t need such a powerful microcontroller to read the impulses from the SBM-20 tube and publish them via MQTT, but to be fair, the chip has a number of other duties. It’s handling the WS2812 RGB LEDs that go off in response to detected particles, running the (apparently optional) 2.9 inch WaveShare electronic paper display, and also pulling data from a BME280 environmental sensor as well as a CCS811 VOC sensor — so it’s keeping fairly busy.
As impressive as this build is, we do hate that it had to be built. From certain world leaders dropping casual comments about the strength of their nuclear arsenal to foolhardy attempts to capture the Chernobyl power station, having access to a reliable Geiger counter isn’t an unreasonable precaution right now. For everyone’s sake, let’s hope the fancy RGB LEDs on this particular build remain as dark as possible.
Head for the hills!! We’re all doomed! At least that’s the impression you might get from the headlines about the monster Earth-facing sunspot this week. While any sunspot that doubles in size within a matter of days as AR3038 has done is worth looking at, chances are pretty low that it will cause problems here on Earth. About the best this class of sunspot can manage is an M-class solar flare, which generally cause radio blackouts only at the poles, and may present a radiation problem for the crew of the ISS. So no, this sunspot is probably not going to kill us all. But then again, this is the 2020s, and pretty much everything bad seems like it’s possible.
Speaking of bad outcomes, pity the poor Sonos customers and their ongoing battle with the company’s odd “glitches.” For whatever reason, customers have been getting shipments of Sonos products they never ordered, with at least one customer getting over $15,000 worth of products shipped. The customer reports ordering five Sonos items, but the company saw fit to fill the order six times, stuffing their apartment with goods. Sonos doesn’t appear to be doing much to make it right; while offering the customer free shipping labels to return the goods, they were expected to schlep the packages to a UPS store. And then there’s the money — Sonos charged the customer for all the unordered goods, and won’t issue a refund till it’s all returned.
If you’ve ever wondered exactly what the signals going up and down your cable line look like, you’ll want to check out this video from Double A Labs. Using an RTL-SDR dongle and some spectrum analyzer software they probed the RF signals on the cable, with some fascinating results. The first 11 minutes or so of the video are devoted to setting up the hardware and software, although there is some interesting stuff about broadband network architecture right up at the start. The scans are interesting — you can clearly see the 6-MHz quadrature amplitude modulation (QAM) digital channels. We were surprised to learn that these start at just about the FM broadcast band — about 108 MHz. There were a couple of little surprises hiding in the spectrum, like two unmodulated analog TV carriers in one spot, and the fact that there are over 400 virtual channels jammed into 41 6-MHz QAM channels. Broadband indeed.
The tech news channels were recently abuzz with stories about strange signals coming back from Voyager 1. While the usual suspects jumped to the usual conclusions — aliens!! — in the absence of a firm explanation for the anomaly, some of us looked at this event as an opportunity to marvel at the fact that the two Voyager spacecraft, now in excess of 40 years old, are still in constant contact with those of us back on Earth, and this despite having covered around 20 billion kilometers in one of the most hostile environments imaginable.
Like many NASA programs, Voyager has far exceeded its original design goals, and is still reporting back useful science data to this day. But how is that even possible? What 1970s-era radio technology made it onto the twin space probes that allowed it to not only fulfill their primary mission of exploring the outer planets, but also let them go into an extended mission to interstellar space, and still remain in two-way contact? As it turns out, there’s nothing magical about Voyager’s radio — just solid engineering seasoned with a healthy dash of redundancy, and a fair bit of good luck over the years.
