Re: Sync Motor Conversion (strobes)
Run a string of bright LED's off AC. They will flash at the line rate. And,
if the forward drop on the diodes is chosen right, relative to the
excitation voltage, the pulses are substantially less than 8.3 mSec long.
For instance, 3 LED's with 2V each Vfwd run off a 6.3VAC transformer will
only really light up as the transformer voltage gets above about 5 V (The
current (and brightness) is a very nonlinear function of Vfwd). You might
not even need a series resistor.
Also, a NE-2H with the appropriate current limiting resistor works pretty
well as a strobe, if you hold it up close to the disk.
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Sync Motor Conversion
> Date: Saturday, June 26, 1999 8:00 PM
> Original Poster: Terry Fritz <twftesla-at-uswest-dot-net>
> Hi All,
> Following the instructions that have been floating around. I converted
> new 1/4HP AC motor to a really nice 1800 RPM salient pole sync motor. It
> was very easy. The instructions I used are at:
> The motor comes apart easily. I covered the bearings and other parts of
> the rotor in plastic wrap to keep out dust. I used the shorting turns
> around the rotor as a guide to where the four flats should be ground. I
> then just let an angle grinder with 60 grit do the work. You only have
> remove about 0.050 inches of material so it is not to bad. A little
> is needed to keep the grind flat but it was no big deal. Just keep the
> grinding disk flat against the rotor. I tried to remove an equal amount
> material and all that but it was easy to do and I don't think you could
> mess it up too badly (on a 1800 RPM). It took about an hour. I highly
> recommend this to anyone with a vise and an electric grinder. Although,
> one can "imagine" doing it with a file, I think the grinder is far far
> easier. Well worth renting.
> I would imagine the 3600RPM conversion would be much more difficult due
> the larger amount of material you have to remove and the more critical
> Although not the greatest bit of Tesla coil technology. I have a big
> file of a strobe disk below. I find it very useful to print out on nice
> paper and stick to rotors.
> Florescent lights give a very nice pattern. However, it would be nice to
> have a fast, simple, cheap, etc. strobe light. I was wondering if a MOV
> about 160 volts breakdown and a current limiting resistor in series with
> florescent or other gas tube simply run from the AC line would do the