Perovskite Solar Cells Printed on Steel

Solar cell made from perovskite

This is about ongoing research, not finished products. Tata Steel, India, and Swansea University, Wales, UK have announced collaboration on research to print perovskite solar cells directly on steel used for roof panels.

(Photo courtesy of Solliance, a European partnership focusing on thin film solar.)

Per a recent news release, Swansea brings expertise in manufacturing the printable cells while Tata brings expertise in coatings on steel, and in screen printing. The two have a long-standing partnership

The goal, of course, is for buildings to generate their own electricity. They report success using them on two Swansea University buildings for several years. Several new release articles appeared in July. Here is a link to one, published on If you’re interested, the site also has a lot of other information on perovskite.

So – what is perovskite? I had to look it up. I’m not a chemist and much of the detail was beyond me, so I won’t try to write much here. It’s a mineral with a particular crystal structure known as the perovskite structure. Want more? Here’s a Wikipedia article link. Solar cells aren’t made of the mineral itself; rather, they use synthetic compounds having the perovskite structure. Here’s a Wikipedia article about that.

The news releases, of course, stress the positives. They can be manufactured using widely available materials, using much less energy than silicon cell manufacture. They can cost less and can be printed using techniques such as screen printing. Articles elsewhere say perovskite can have higher efficiency than silicon.

I spent an hour or two reading online. That doesn’t make me an expert, but there are some concerns that people are working on. The compound most used includes lead, raising serious concerns about pollution from discarded cells. Also, their long-term stability at present is limited. Here’s a link to a Wikipedia Perovskite Solar Cell article.

It’s still early. Research continues. I’m betting perovskites will be an important advance.

Tinker Toy Computer

Picture of a tic-tac-toe computer made from tinker toy parts

The ultimate geek project – a computer made from Tinkertoys!

Designed by Daniel Hillis and Brian Silverman in 1978, it plays tic-tac-toe. The 3 x 3 front panel shows the “X”s and “O”s. It is said never to lose. Per a 1981 letter from Danny Hillis, it was built using about 10,000 wooden parts, some fishing line, and sinkers. They designed it using a LISP program on a PDP-10 computer. Danny wrote, “It could have been built by any 6 year old with 500 boxes of Tinker Toys and a PDP-10 computer.” It uses “TTL (Tinker Toy Logic) gates”.

It now sits in the Computer History Museum, Mountain View, California, their catalog #X39.81. You can see and read about it at

Photo courtesy of the Computer History Museum.

Flying Saucers!

Flying saucer picture

Flying saucers were invented – in the popular media – 75 years ago. This post was inspired by a BBC online article ( I’ll just say a few words, then give you the link.

Image by OpenClipart-Vectors from Pixabay.

In 1947 a commercial pilot in the state of Washington reported seeing nine “flying discs” moving at 1,200 miles per hours. A newspaper passed this on, without verification, to the Associated Press. The Hearst newspapers (Hearst International) put out a press release using the term, “flying saucers”. Before long, people all over were saying they saw them. A craze was born!

The BBC article is a fun read. Here’s my favorite. In 1951 Ella Fitzgerald recorded a song named, “Two Little Men in a Flying Saucer”. I listen to jazz and love Ella, but I’d never heard this one before. I listened to it now on the internet. Just a cute little song: it pokes fun at things we earthlings do. My favorite line:

“During their mission, heard a politician making speeches as they traveled by.

But they departed, faster than they started, ’cause the hot air blew them sky high.”

Here’s the link to the BBC article, posted July 14, 2022. I don’t know how long they will leave it up.

By the way, has a lot more than just news. Lots of interesting stuff to read. A good source for international news, too. Try it out!

How I Became Treasurer

Clubhouse, Casa Del Sol condominium

Me? Condo treasurer?

When we moved to our condominium I said, “I’ll help, I’ll volunteer, but I’ll NEVER serve on the board.”

Picture: Casa Del Sol condominium, Sarasota, FL

Almost four years ago our board’s treasurer, Mike, moved and so had to leave the board. He remained nearby and was gracious enough to continue as “assistant treasurer”, with the board’s approval, until a replacement was found. Our president, Donna, spent the next three months begging for someone to volunteer. She would say, “It’s not that hard.”

My wife, Jacquie, and I talked it over. I was semi-retired – consulting but not formally employed – so I did have the time. We said, “Well, I guess it’s my turn.” It was December. When I told Donna she said, “Thanks – I guess you’re my Christmas present!”

My background is electronics, not financial. I’ve never had so much as a single bookkeeping course. Many years in engineering management at other companies, though, plus running our own business, had been good on-the-job training. Mike, fortunately, was still available and was a big help getting me started. Donna had been treasurer before him, and the condo’s finances were in good shape. We still see Mike around. Donna recently passed away. Sad – she was a hard worker and we all loved her.

“It’s not all that hard”? Depends on your point of view. It took a fair amount of time. Some people told me mine was the hardest job, but I disagreed. It felt less stressful than other board positions. I could do much of my work at home with my computer. Others got more involved with irrigation and pool heating failures, landscaping details, illegal parking, tree trimming and owner complaints. Also – rules & regulations! How many flowerpots – what can we hang outside – approved plant lists – can the owners have gas grills – etc. etc. I was involved, but others carried more of the weight.

The plus side: ours was a good, co-operative board. No politics. I made some good friendships.

I’m finished now – did not run for re-election after serving three years. I feel good that I helped. We very much love our condo and most of the people in it.

We got lucky with my replacement, Ranita. She has many years of condo management experience and comes with ideas on how to make things easier. I’ll help her as needed.

Affordable CAD

I recently reached the point where I needed to find affordable CAD (Computer Aided Design) software. I’m primarily an electronics designer, not mechanical. When I was young my drafting courses used a drafting table, paper, T-square, triangles etc. My first circuit board layouts were done on mylar, using tape and stick-on pads. When I started using circuit layout software I learned also to use it for simple drawings with lines and circles.

I’d never used nor studied CAD, so my search comparisons were based strictly on stated capabilities, reviews, references and, of course, cost. I wanted to pay hundreds, not thousands. I found TurboCAD and selected one of its lower-cost versions, about $200 at the time (2017). I then became too busy to learn and use it. Now, I’ve started.

TurboCAD, even the lower priced version, has so many features, functions, settings and capabilities that learning it has been a mind-blowing experience for this novice. I suspect an experienced CAD user would find it less difficult. They have many excellent on-line training videos: I’ve studied several of them. My approach is to open TurboCAD, start the video, then pause it while I test doing what they’ve just said. One thing I’ve learned is, the videos move pretty quickly. Pause, go back, repeat and write notes. My problem has been, I later remember what they did but not where to find it in the many, many menus. The “help” part of the program is not very good.

I’ve not yet gone beyond basic two-dimensional drawing. Other capabilities include 3-dimensional views and architectural drafting. I’ll probably never study nor use all it can do.

I’m writing this only to share what’s worked for me in case you, too, are looking for affordable CAD. It’s not a recommendation or endorsement. TurboCAD has not been involved in writing this, although I will share it with them after it’s posted. I’m not a drafter or mechanical designer, and it’s the only CAD I’ve ever used. There may be similar offerings from other companies, but I’ve never used them.

If you’re interested, the site is They offer several versions, with a wide range of prices. I’m using TurboCAD Deluxe, a lower-priced offering.

Sine – Cosine Approximations

OK, this is supposed to be a technical web site. It’s about time I posted something technical! Actually, this is just a link to a white paper I posted in the Digital Designs section.

Sine and cosine functions, showing how they are used to set a circular position.

A microprocessor-based design needed to create a circular motion by using the cosine and sine functions to drive X and Y positioners. The exact equations for these functions are infinitely long polynomials, so approximations are needed. We studied three possibilities, each with different tradeoffs between accuracy and speed.

If you ever need to compute sine and cosine, here’s the link: White Paper: Simple Sine Approximations.

Why SRQ?

Aerial drone view of Siesta Key Beach in Sarasota, FL

SRQ Technology? What a unique name! What does SRQ stand for?

Good question. It’s not anyone’s initials. I’ve racked my brain trying to think up something catchy. Maybe Superior Reliable Quality? Supplying Results Quickly? Solving Rough Questions?

Don’t like those? Well – let’s try Stinking Rotten Quagmire, Stop Ridiculous Quibbling or Seems Really Quirky. Ugh! Enough!

OK – SRQ is the official designation for our Sarasota-Bradenton (Florida) International airport. I read that around 1956, when the three-letter designations were created, SR was felt to be recognizable as Sarasota. Q was added to make it unique. Since then, it’s become the local shorthand for Sarasota. We even have an SRQ Magazine. (Also, Sarasota Magazine.) I did a bit of searching and found:

  • SRQ Custom (auto customization)
  • SRQ Fabrications (also auto related)
  • SRQ Media Group
  • SRQ Vets
  • SRQ360 Photography
  • SRQ Blinds and Drapes
  • SRQ Woodwork
  • Gym SRQ
  • Lab SRQ

And a few others. So, SRQ Technology isn’t so unique after all.

Now, the commercial. Please keep us in mind if you need circuit design or technical writing services.

My Electronics Workbench!

Electronics workbench, but covered with woodworking projects.

Warning – commercial coming!

Here’s where I breadboard & test my fantastic electronic creations. Look – you can see an oscilloscope, a small meter and part of a lab power supply! The soldering iron is almost hidden behind the saw.

But now, honey-do time. My wife, Jacquie, makes and sells fashion doll (Barbie) accessories. Much of what she does involves clay and resin casting but when she needs wood pieces for furniture and lamps, that’s where I come in.

I enjoy it. I’ve always liked working with wood. Not a master craftsman, but I’ve built a few cabinets, shelves and display tables. Just stained plywood, nothing fancier.

Barbie/fashion doll accessories including chairs, a lamp and a rug.

Now, the commercial. She has a business – sells her Barbie/fashion doll crafts on The direct link to her store is Why the name? She started with Barbie-size food, dishes, dinners etc. and Barbie is 1:6 scale. Here’s an example of her furniture.