Flasher Fun

With the Keck Observatory open house approaching I am helping get one of the most popular activities ready. At the last two open houses we have made flasher pins, we will do so again this year.

Flasher Pin
A simple electronics project… The Flasher Pin
Flashers? These are a simple circuit built on a PCB that flashes a pair of LED’s. Nothing serious, just a bit of electronics fun. The activity allows folks to learn a little electronics and soldering.

The PCB is configured as a pin or badge, with a brooch pin soldered to the back that also serves as a switch to turn on the LED’s.

The original design came from John Maute at SAO. The circuit is based around the venerable LM555 timer IC configured as an astable multivibrator. The LM555 timing circuit is simple enough to solder together in a few minutes, complex enough to look cool and provide a real introduction to an electronic circuit.

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New Front Bearings for the Ford Explorer

My vehicle comes to a rather abrupt stop, the front brakes lock up while pulling onto Paniolo drive, the main road serving the village. I am stuck across the northbound lanes.

Ford Explorer Front Bearing Repair
The front bearing of the Explorer removed and the mounting cleaned up. Ready for re-installation!
Well? This is awkward.

Shut down, restart, nothing unlocks the brakes. I am still stuck in the middle of the road. Another driver gives me a quizzical look and drives around me.

With no other idea I put the vehicle in 4WD low and drag the locked front tires backwards into the side street where I can safely work on the issue, I left skid marks in the road.

In retrospect the failure was not a complete surprise… I knew the front bearings were going, making noise, but the vehicle was still driveable. Over the last week I had checked on prices and asked about with the guys about borrowed tools to do the job. I was thinking I had a few weeks before the issue was truly an issue.

Nope.

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Uranus at Opposition

Today the planet Uranus will pass through opposition, directly opposite the Sun in our sky. The planet will be well placed for observation all night long, rising at sunset, transiting at midnight, and setting at sunrise. If you are looking to observe Uranus, it is currently shining at magnitude 5.7 in the center of the constellation Pisces.

Uranus
The planet Uranus as it appears in a mid-sized telescope
As the outer planets Uranus and Neptune move so slowly across the sky, the timing of oppositions is driven by the Earth’s orbit and occur each year at nearly the same time. The orbital period of Uranus is 84.1 years, taking the better part of a century to circle the celestial globe once.

Mercury at Superior Conjunction

Today Mercury will be at superior conjunction. After today the planet will reappear in the evening sky, rising high enough from the Sun’s glow to be seen around the end of the month.

Mercury Transit 9May2016
Mercury transiting the Sun on May 9, 2016. Celestron C8 and Canon 6D at f/10.
Superior conjunction is when the planet passes around the far side of the Sun as seen from Earth. For a few weeks the planet will be lost in the Sun’s glare, hidden from view.

As Mercury is on an orbit inside that of Earth’s it will see both inferior and superior conjunctions as it passes from the evening sky to the dawn sky and back again.

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