Recent content by dr-ebert

Completely wrong, of course. Under the influence of earth's [standard] gravity, a mass of 20kg has a weight of 20kg *). You might as well argue that a thermometer doesn't show the temperature but just a certain length of mercury (or colored alcohol) thread. *) Ignoring the buoyancy caused by...

Actually it's known since about 150 years that diamonds upon burning up produce a bit more energy than the equal weight of coal, due to the energy stored in their tighter bonds. Also at that time, a diamond was converted to carbon by focusing sunlight on it, with the diamond in vacuum under...

Drivers don't stop working when the input voltage is too low (that would require an undervoltage detection capability), they just try to give as much current/voltage as possible. They're not actually regulating any more in this situation, that's why it's called "out of regulation". The...

That's me. I run it at 420mA with nothing but an Aixiz (which is held inside the flashlight host with strips of paper :shhh: ). It takes a minute or so before it becomes unacceptably hot. No problem at all if you just want to point at stars or distant walls a bit. Generally of course I try to...

The flexdriver output voltage is limited to <6V. You can have boost drivers with much higher output voltages (probably even using the same IC, the limiting factor is the Schottky diode), but still combining a boost driver+linear driver would make absolutely no sense. All the linear driver in...

Are you sure the battery is still good (you have to test under load)? I've heard that the 9V batteries aren't really able to deliver the high currents that a LPC needs. How did you set the current? As the diodes age, especially when they're overdriven (or overheat), it's possible that the...

Actually they do. It's more a sort of braille printout, a line with pins controlled electromagnetically at the top of the keyboard. It might be that there's something doing graphics as well in the meantime. Also... you're 28, your son is 13? There are more dangerous things to do at age 13 or 14...

Of course it will work, it just won't be very good. You need a reasonable contact between layers (no need to get all the air out). To get rid of trapped air bubbles, maybe punch some needle holes through the layers. Considering that I'm currently using paper wrapping :shhh: to hold the Aixiz...

Depends on what exactly got killed. I think it's a good chance only the driver died, not the pump diode (it should be able to withstand that much reverse polarity unless you've got a boost driver inside - having an inductance would be a telltale - but probably not even then); the crystals don't...

The diode die is very light - on the order of micrograms. Thus it has virtually no inertia and will be able to handle very high accelerations. The recoil of a gun isn't that much, in the order of 100g's if you hang it by a thread (a washing machine at 1000rpms generates as much :) ); much less...

Drive current? Which lens? Wavelength is more 660nm normally.

I ordered it too 4 days ago, today I got a refund from FP. Tough luck. As they say, if it sounds too good to be true...

In the german wiki it says that the processing of BeO is strictly controlled since 30 years, but it's not clear whether that means "in Germany" or worldwide or what exactly constitutes "processing". In any case, knowing the ceramic is a potentially serious threat, it should be treated as...

Contrary to what HIMNL9 wrote, surface roughness and reflectivity are completely unrelated. Reflection can be direct (mirror) or diffuse (white wall). The corrugated ("orange peel", OP) reflectors, commonly used in LED flashlights to create a more even beam, don't lose light, they just...

And you still couldn't figure out where the (quite well-known) quote was from? Weird.