What’s Inside A Lightning Arrestor?

What is inside one of those things? The folks over at Northstreetlabs have set out to answer just that question. You’ve seen these things before, and if you’re uneducated on the subject like myself, you just assumed they were there to stop a possible connection from a power line to the pole/building to which it is attached. Apparently that is part of their purpose. When presented with lightning, however, they turn to conductors allowing the lightning to pass to ground.

You can see their teardown in video form, as well as an explanation of how exactly they work on their site.

DIY Lightning Special Effects

Halloween may have come and gone but thats no reason not to take a look at this neat little special effects setup.  Basically it uses an analogue circuit to monitor an audio signal and triggers some camera flashes using 5V relays.  The idea is that you can play lightning strikes and other spooky sounds, and the system will trigger camera flashes to coincide with the lightning strikes. Adding in some color organs in addition to the camera flashes will dim your lights to help achieve a thunder like effect. Unfortunately there aren’t any schematics for the color organs (which technically might be just light organs) but that doesn’t detract from the seemingly well designed analogue signal processing. Check it out in action after the break.

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Marx Generator, Knocks Our Rocks Off

What weighs more than 500 pounds, produces 500 kilovolts, and we don’t recommend you try at home in any way shape or form? If you guessed a rock disaggregation device, you’re correct! We also accepted lightning generators as correct answers. Using high voltage electricity, a rock can be split apart down to its grains without destroying the precious minerals inside; unlike traditional grinding and mechanical techniques that often ruin the sample. All it takes is a massive hydro pole transformer, five 1uf 100 kilovolt capacitors, eight hand wound inductors, and two massive cojones to stand within 20 feet of the thing while it’s going off. Video after the divide.

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Camera Lightning Capture


The people at [Hobby Robotics] decided to build a trigger circuit for lightning photography. There are more complex ways to do this, but they just used a photo transistor and an Arduino. The Arduino watches the photo transistor’s value and compares it to the previously captured one. If the difference is above a certain threshold, it means a rapid change in the amount of light has occurred, which triggers the shutter. An earlier post covered how to directly control the Canon 30d using an Arduino. All of this works because the shutter lag and code execution together are less than lighting’s 100ms duration.