Member Since: March 25, 2008

Country: United States

  • The fuel shutoff switch is also important during the start of a turbine engine. No fuel is to be delivered before the turbine is at the start RPM, with ignitors on. Otherwise the engine can start with a bang. (This is bad news when it happens.)

  • A LED’s light output is a function of the current flowing through it, not voltage applied to it. The voltage required to achieve a desired constant light level output from a LED varies with temperature. This is why driving them with a constant current source is a good idea.

  • Inserting a double length header and plugging it into a breadboard? Most breadboards would short out the odd and even pins on the connector as they are designed for .300" PDIP parts. Perhaps a PCB is in order to allow the header to be properly broke out on a breadboard.

  • Awesome event! However next year the airborne portion may need to be different due to the FAA’s recent reinterpretation of its rules.

    For those interested, here is a link:!documentDetail;D=FAA-2014-0396-0001

  • After a simple modification, he will never forget his safety glasses again!

  • Yes, it should work fine. Since you will be pointing the sensor upwards towards the sky you will want to protect it somehow from rain/dirt/etc.

    You could use a germanium window, but that is a bit costly. A window made of thin plastic wrap will keep moisture and dirt from falling on the sensor while being essentially transparent to the infrared. It will not be as durable as the germanium window however.

  • When you relocate the feedback pot, it is possible that the two end connections to the pot will need to be swapped. The reason for this is that depending on which side of the gear train you attach the pot from as well as the number of gears in the gear train may be different and could cause the final arrangement to differ in rotational sense than that in the original servo.

    If the rotational sense is different than the original, the servo motor would turn, which would cause the final shaft to turn as well as the pot, but in a direction that will set the pot to a voltage that is further not closer to the desired voltage. It will keep on turning in this direction until it hits a mechanical stop. If you hook it up this way and the pot has internal mechanical stops, the likely result will be a damaged pot unless you remove power before it hits the mechanical stop on the pot.

    Test the configuration by temporarily removing the gear which drives the pot. Then manually turning the pot in the direction the gear would be driven when the servo is commanded to change to a new position. This will determine if you need to swap the leads on the pot or not.

    If the motor stops before you hit the end limit on the pot, the sense is correct. If not, and it stops if you turn the pot in the opposite direction than the output gear would have turned the pot, you need to reverse the two outside leads on the pot.

    Hope this is not too confusing.

  • You short changed the processor speed on the Beaglebone Black a bit, it is 1 GHz, not 800 MHz. The product page has it correct.

  • The banding seen is caused by the fluorescent light illumination interacting with the sampling of the ccd sensor on the pi. The florescent light pulses on and off 120 times a second, which when sampled by a digital signal processing system can cause aliasing, which is seen as the dark bands seen in the movie.

    To avoid the banding, consider using incandescent illumination during the photos since they pulse significantly less than fluorescent lights. Incandescent illumination will provide more natural looking photos as well.

    To explore the effect of aliasing with digital video cameras, one could use a LED array driven by a frequency generator noting the various effects as you change the frequency the LEDs are pulsed.

    Next summer, you might consider setting up a time lapse sequence of a field of sunflowers as they track the position of the Sun during the day. This is Nature’s version of people watching a tennis match.

  • Is this a type of “Method 1” hacking?

No public wish lists :(