Re item 1 above - I believe that subways and trolleys still use vacuum incandescent bulbs (at least they used to). They would run five 120V bulbs in series for lighting (5 x 120 = 600 - the third rail voltage). I remember seeing these five bulb arrays in the NYC subway in the past. You would probably have to go through a specialty electrical supply house to get them - or your local trolley museum.
- Jim D On Wed, Jul 16, 2025 at 12:17 PM William Beaty <[email protected]> wrote: > On Sun, 13 Jul 2025, Robin wrote: > > > 1) wrap a coil around a strong magnet (or maybe just an Iron rod?), that > is aligned with the Earth's magnetic field, > > such that the Earth's field lines are concentrated in the body of the > magnet (or Iron rod). > > 2) Attach a capacitor to the coil such the resonant frequency of the > tank circuit matches the Schumann resonance. > > 3) See if any energy can be harvested from the circuit. > > Tesla was working at 1KHz, sometimes 5KHz. The Corums ran simulations > with planetary Zenneck surface waves and supported this, also finding that > 10KHz and above was fairly useless, and above 30KHz insignificant. Tesla > said the same, discovered from experiment. "Earth resonance" is a 1KHz > phenomenon. (Plus all the overtones of 11.8Hz, or of 8Hz if you prefer.) > > So, just need to wind a 1KHz LC resonator, with extremely high Q. Provide > lots of side-taps, and add a series of low-loss 1uF capacitors. I think > you can get huge litz wire from cheap $10 induction cooker coils sold on > eBay. Also, low loss HV 0.33uF capacitors for induction cooker main tank > circuit. > > More practical would be to experiment with the Sutton Spaniol active VLF > antenna, to verify the physics. Never tried it myself. Their trick is to > make a perfect conductor by the same method as superregen radio: add an > active circuit for negative resistance, in parallel with the loop antenna, > adjusted to cancel out the resistance of the coil and capacitor. It's a > DIY hobbyist superconductor resonator. I did build one of these > canceled-resistance inductors. It acts just like a hall-effect sensor, > since it integrates changes in magnetic flux (it linearly detects > approaching magnets, just like an analog hall sensor does. Use this as > arrays, to build superconductor shield panels. Weird battery-powered > superconductor phenomenon.) > > So, we must adjust our Sutton/spaniol antenna for stability while > shielded, then remove shielding and see how large a wave appears. It will > SEEM to be unwanted oscillation. That's what conventional hobbyists would > expect, and they'd simply ignore the results. (Probably a gigantic 60Hz > and 120Hz wave appears. Ignore it as unwanted noise? But what if you're > actually seeing resonant power-theft, with significant wattage!) > > But, if you intentionally built an "artificial" superconducting coil, then > obtained some massive received signals, we should properly put it down > to "mag > loop" physics, and ascribe it to all the weird results seen with > electrically small > radio antennas having immense Q-factor. (Heh, it's an infinite Q in this > case, same as supercon loops.) If any resonant RF signal impinges on the > coil, a sine wave should > start ramping up and up. It will stop increasing as soon as the radiative > losses from loop-antenna's transmission are equal to the incoming received > signal. Much like charging up a capacitor from ambient DC e-fields, but > in this case it's the oscillatory analog. > > The Corums say this doesn't work, because the sharp Earth-resonances > wander around on a time scale of ~20 seconds. So, you can never get the > tuning of your resonator correct. It would somehow have to track the > moving planetary resonances in realtime. > > But the Sutton-Spaniol "black hole antenna" includes a negative inductance > circuit. That way it behaves just like a tuned circuit, while also being > broadband, and building up huge sine waves of any incoming frequency. > > I think these weird VLF devices are ignored because if they show > unexpected results, everyone insists that it's just self-oscillation, some > sort of unexplained circuit-instability, and couldn't possibly be caused > by the physics of high-Q receiving antennas. (The situation is analogous > to having a real FE device, but where it required batteries in order to > produce the bizarre effect. Nobody will believe that it's real, > regardless of measurements. The presence of a DC power supply is > driving skeptics crazy.) > > Heh, so just use a Sutton-Spaniol antenna to extract enough ambient VLF > power that we can close-the-loop and power the several FET op-amp stages. > Let the antenna-coil grow warm. Plus a bank of light bulbs too? > > PS > > Tesla secrets, dunno if I put them here before... > > 1. an incandescent light bulb will light up when held near a Tesla coil. > Even a BD-10 hand-held "violet ray" T.C. can light a tungsten bulb via > ionic impact (it's "Tesla carbon button" mode.) But the bulb must contain > hard vacuum, no argon gas. Aquarium bulbs and lectern bulbs are that > type. So are the 7.5W and 15W "golf ball" incandescent lamps. > > In other words, when Tesla plugs a huge light-bulb into the Colorado > Springs dirt (in that Beograd Tesla movie,) that easily could have been > real. But you'd need a pre-1930s antique light bulb, if you wanted to try > it today. > > 2. I recently realized that the secondary of a Tesla coil is also a > microwave resonator. The stack of windings is a dielectric transmission > line, a conductor of displacement current. In pulse mode, and running at > high voltage, it could put out VHF or even GHZ pulses of stunning peak > wattage. How? It's because a single cylindrical coil is the same as a > stack of parallel-plate capacitors in series, like a tall stack of > electrically-floating copper disks. EM pulses jump directly from disk to > disk, going at a foot per nanosecond (that for a coil in air, slower for > one embedded in urethane varnish. That's the usual physics of a > resonator, when operating far above resonance. And also, a long long > stack of close-spaced metal disks is an odd type of transmission line, and > can guide EM waves. > > Far below resonance, The same secondary coil acts like a very long wire, > where an EM wave has to follow the length of the spiralling wire (perhaps > becoming a 200KHz quarter-wave resonant stub.) > > So, when Tesla discharged his coils, using a megavolt spark-gap (with all > plasma-streamers inhibited,) he was exploring a regime of few-nanosecond > pulses, with peak currents similar to that of huge capacitor banks, and > peak-powers of unknown megawatts. Hundreds, thousands of megawatts? But > only five or ten nanoseconds duration, as the "discharge wave" proceeds > down his extra-coil at lightspeed. It's not a coil, instead it's a > capacitor with very thick dielectric, where a discharge is mostly a > displacement-current between the parallel wires. > > He reported having discharges which violently exploded his wooden coil > structures. But today the big tesla coils never do that! (Big tesla > coils are supposed to make fractal lightning bolts. Tesla considered this > a malfunction. Yet today, if your large tesla coil DOESN'T make any > fractal lightning bolts, you'll consider THAT a malfunction.) > > So, build a ten kilowatt TC, suppress all lightning, then crank up the > power, and see if instead it makes deafening bangs, and dangerous plastic > shrapnel. But perhaps you'd need a megavolt spark-gap in order to see > this sort of discharge, while suppressing the slow-growing plasma- > streamers. Your secondary has become a half-megavolt capacitor bank. > (What's the series microfarads of the secondary of a floor-standing tesla > coil, if all the turns are sliced, so they behave as a tall stack of > separate rings? Knowing that, we could calculate the stored joules, and > the peak power in a few-nanoseconds pulse. Try all this stuff at 20V > first, with mercury-wetted contacts, oscilloscope compatible.) > > > (((((((((((((((( ( ( ( ( (O) ) ) ) ) )))))))))))))))) > William J. Beaty http://staff.washington.edu/wbeaty/ > beaty, chem washington edu Research Engineer > billb, amasci com UW Chem Dept, Bagley Hall RM74 > x3-6195 Box 351700, Seattle, WA 98195-1700 > >
