Author Archives: gregorykimball

USB toggle switch extension

Last week I found myself in need of a USB toggle switch.  Such a device would allow me to toggle the power on a USB device without having to unplug it.  It is true – I suffer from a disorder that requires me to construct a USB switch rather than simply unplug my devices.

This simple device uses a USB extension cord and a slide switch connected to the +5V power line (the red wire).  If you happen to have a device  [such as an external video card] that requires to be reset every few days, simply toggle the switch when a reset is needed.

usb power switch Continue reading

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I can see sunspots

I have been on a bit of a quest to observe the sun effortlessly, without discomfort, and with my own eyes.  There are plenty of great photos and videos of the sun in different wavelengths, but experiencing the sun without any digitization or intervening detectors has been a goal of mine.

I can finally report the combination of filters that allow anyone to comfortably view the sun.

solar_viewing_glasses Continue reading

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That Caltrain life

I’ve been spending a lot of time on the Caltrain and my impression has been generally positive.  If the SF bay area cannot manage to get public transportation working in the peninsula, at least there is a competent private transportation alternative.

bike car from hell Continue reading

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Guaranteed Texas Crude Oil

I just completed a purchase of some additional crude oil samples to add to my collection.  Here is my new favorite:

black gold, certified Continue reading

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$50 electronics test bench

I’ve been having a hard time finding oscilloscopes and adjustable power supplies in the “hobbyist” price range, but I think I have cobbled together a solution.

A few key components:

  • Power supply from old PC
    • Make sure to short the correct pins to trick the power supply into turning on.  This is usually green to black.
    • yellow-black is 12 V
    • red-black is 5 V
    • orange-black is 3.3 V
    • If you want other voltages, well..  time to built a buck-boost circuit!
  • Gabotronics Xprotolab mini oscilloscope
    • 2MHz sampling
    • 8 bits resolution
    • $50 (the best part)

test_bench_1 Continue reading

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Solar-powered boat!

I recently took a trip to Alcatraz island to see the @Large Ai Weiwei art exhibit.  On the way to the island, I was delighted to find that my ferry was solar-powered!

pv on a boat Continue reading

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Engine information

One of the perks of having a modern vehicle is that you can use devices to monitor the engine and drive train performance.  I was recently using my Vgate Bluetooth Scan Tool OBD2 Scanner to record speed and engine RPM values during a short trip.  In the following plot, you can clearly see the six gears of the automatic transmission as straight lines in speed vs RPM.

speed versus RPM Continue reading

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