Over the years, I have had more than my fair share of computer equipment destroyed by lightning. Even with good surge suppressors, I still seem to loose parts of computers.
Do I live in Florida where they get daily lightning storms? No. I have lived in New York and New Hampshire where wee see perhaps a dozen storms a year. Chalk it up to bad luck.
But perhaps I could spare some of the problems if the storms passed with all my computers shut off. I know that NOTHING will prevent a direct strike. Not even completely unplugged computers. But you can reduce the risk if your computer is at least shutdown and preferably unplugged from power and internet.
But storms often pass through during the day when I am at work unable to attend to their needs. Now my wife works from home and could help out, but in her studio in the basement, she often only hears a storm when they are right on top of her.
And hence the desire for a lightning detector. Something that could warn my wife of impending storms so she can shutdown her computerized sewing machine, and something that could at least turn off our computers.
The initial spark came from an article in Nuts And Volts magazine many years ago. When I decided to build a detector, I could no longer find the article. So, I went to the web in search of a design. I found several circuits, but none really appealed to me. They required hard to find parts, hard to make RF circuits, or difficult to interface a microprocessor to.
So I started from scratch with the basic information I could remember from the article: 50 turns of wire around a 1 foot circular form.