Bill Yacey

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About Bill Yacey

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    Creator of Fine Shavings

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    St. Albert, Alberta, Canada

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  1. This is true that absolute measurements cannot be made, however comparisons can be made against an incandescent bulb, as an example.
  2. I'm assuming a standard cheapo, non balanced input sound card. Ideally, the photocell should be enclosed in a shielded enclosure to eliminate the majority of external electrostatic noise from being coupled into the pickup lead, with a window cut-out opening for the light to pass through. The connecting lead should be well shielded cable too, and connected to the metal enclosure. The soundcard doesn't need to operate down to DC; the main frequencies of interest are 30Hz and up, in this case. At a distance of a couple feet away from the light source, induced AC hum shouldn't be an issue.
  3. Most of these editing softwares have a "Remove DC offset" function in the sound card settings.
  4. Have a look here: http://www.sengpielaudio.com/dB-chart.htm Field Quantity Voltage converter; this will give you accurate calculations. I use the 6db rule for estimating.
  5. Every 6db is a halving or doubling of voltage with respect to the reference value.
  6. This would work, but the problem arises when you want to switch off the light; it'll remain lit until the battery goes dead. A filter capacitor on the output of the supply would do the trick, but I suspect manufacturers are avoiding this because (1) It drives up the cost per unit slightly. (2) The lifetime of the actual LED would be reduced because it is on 100% of the time, instead of being switched on and off producing a duty cycle something less than 100%. (3) The filter capacitor would be an electrolytic type that doesn't stand up to heat very well. The base of the LED bulbs get warmish / hot due to losses from the switching supply built into them. The resulting heat would shorten the life of the capacitor by slow cooking it to death. (4) The inrush current when the light is switched on would be higher than normal in order to charge the capacitor. This inrush current puts further stress on the switching supply which would require an extra margin of safe operating area for the component specifications which in turn would drive up the manufacturing costs. Points 2 and 3 would considerably reduce the lifetime of the LED lighting unit.
  7. Bill Yacey

    Any good Russian Luthiers?

    The hand written part of the label reads April 1941. Odessa was not the capital of Ukraine then, or ever, from what I'm aware of. It was however, the regional administrative center of Odessa Oblast (province). History gets twisted around in many ways, depending who tells the story, and often times to fit an agenda. Kiev was the ancient capital of the Kingdom of Rus, the ancient name of the Ukrainian geographical region. This doesn't mean that Ukrainians are Russian, nor is the term Rus synonymous with Russian. Kiev was a thriving major city when Moscow was yet a fur trading outpost in the northern wilderness, circa 1000 AD.
  8. Bill Yacey

    Planetary geared pegs

    My experience has been much the same with the Knilling. They slip if the peg head isn't pushed in firmly, which I think puts undue stress on the peg box while trying to tune. Additionally, the gear reduction is too low a ratio making it difficult to tune the E and A accurately, so don't get rid of those fine tuners.
  9. Bill Yacey

    Scroll broke off!

    NSD, I'll bet. = New Strings Day
  10. Bill Yacey

    Scroll broke off!

    Special machine for cleaning up galactic particles and moon dust in zero atmospheric pressure conditions. Most housewives don't bother though.
  11. Bill Yacey

    Scroll broke off!

    Just be careful after gluing it up, should you have more carving to do. I had a scroll break away once, and I drove the chisel into my hand.
  12. Bill Yacey

    Scroll broke off!

    You might have a bad piece of wood there. Those dark streaks like the one running through the A string peg hole sometimes indicates a weak part of the wood prone to splitting.
  13. Bill Yacey

    how and where dobi start

    Whoever refinished has a lot of patience to wait 6 years for the varnish to dry.
  14. For this application, the best situation is to not flash the LED on and off at all, essentially running on clean, ripple free DC. I thought about the possibility of running low voltage LEDs in the home residence, but the lighting circuits would all have to be re-wired for DC low voltage.
  15. No, if the DC is properly filtered and regulated, there isn't any ripple component.