Every real man needs at least one silly hobby.
Mine is repairing, redesigning and (as a result, sometimes) ruining flashlights.
It started when the white led was invented. For quite a while, there were
no good led-flashlights on the market yet, and you could build a better one yourself
by buying leds at an electronics supply store and powering them
with the Li-ion battery from a laptop.
By now, you can buy a high-power led-flashlight with sophisticated power management
for a few euro's, so building them yourself makes no sense anymore.
Also, the parameter space for flashlight-design is rather limited.
In other words, after a while you've seen it all.
Perhaps I should switch to doomsday prepping.
King size flashlight, 12 volt, 50 watt halogen bulb. Lead-acid batteries, 2 x 6v x 4.2 Ah
(light time theoretically ~1 hour, in fact more like ~30 min).
It's more than ten years old, the batteries died, does not work anymore.
It may seem silly to use a cordless, rechargable lamp in your own living room,
but in some places it saves a lot of hassle with cords. This one (1.6 W led-bulb) lasts for ~ 45 hours. So if you use it for ~2 hours every night,
you need to recharge it only once every three weeks.
This battery (12 V, ~200Wh) came out of one of these gadgets that claim
it can start your car when the battery is empty (it can't).
It can power a lot of led-light, though.
The rotating light-bar has a 3x3 W, a 3W and a 1.3 W unit.
With everything switched on, it lasts 15 hours, with only the 1.3 W bulb on, about a week.
A 360 degree horizontal panorama from stitched-together pictures
is a well known camera trick. But what is the result if you do this vertically?
When you've never seen one, it's kind of hard to imagine.
Regular camera tripods can't do this, so I made this rather crude device for a 360 degree vertical tilt.
See the picture page for a vertical panorama, stitched from 12 pictures.