[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

*To*: tesla-at-pupman-dot-com*Subject*: Re: Voltage profile on the secondary*From*: Terry Fritz <twftesla-at-uswest-dot-net>*Date*: Sat, 10 Jun 2000 20:13:48 -0600*Approved*: twftesla-at-uswest-dot-net*Cc*: "Robert Jones" <alwynj48-at-earthlink-dot-net>*Delivered-To*: fixup-tesla-at-pupman-dot-com-at-fixme*In-Reply-To*: <002f01bfd334$7bd9e1a0$03000004-at-oemcomputer>

Hi Bob, I measured the profiles for may bare 10.25 inch dia. 30 inch long secondary (75.4mH 1000.5 turns) at: http://users.better-dot-org/tfritz/VoltDistBare.jpg and the top load case at: http://users.better-dot-org/tfritz/VoltDist.jpg with the raw data at: http://users.better-dot-org/tfritz/voltagedist.xls I took a tiny voltage probe feed to a scope to measure true RMS voltage. I tuned a constant voltage source (low-Z sine wave) and adjusted the frequency slightly to account for the slight loading of the probe and ran it along the length of the coil taking the readings carefully at each point. I had no primary, quench, or anything else involved. Just the secondary coil, sine generator, and scope.. I compare the secondary voltages from those readings to a sine distribution and an l^e distribution in the graph at: http://users.better-dot-org/tfritz/DistGraph.jpg I use these measured distributions to come up with the voltage distribution functions in E-Tesla5 which I now go in and average at one point to get greater accuracy. The resulting distribution in that program for a terminated coil looks like: http://users.better-dot-org/tfritz/Jdst1.gif One will notice that the distributions I got are not sine functions! They are power functions. I used l^e but it may really be l^2 (or a torque summation). I think the voltage rise is much more like a bent ruler as Malcolm suggests and not like a sine wave. However, the harmonics are much more sine like in their distribution but they may also actually be a power function. A bent ruler is a summation of the masses and gravitational forces along it's length and the resulting torques and the spring constant. Very similar to a sine type of oscillation. However, if one compares the displacement along the wire, it is a bending function not a sine function. Although the secondary coil in E-Tesla5 is affected by the surrounding primary, walls, top terminal, etc., they are all set to zero volts and assumed to be grounded. E-Tesla does not assume any frequency , quench, arc / streamer loading, or mutual coupling effects. I just set the secondary voltage distribution to about what my measurements showed and let it crunch away. My new correction step in version 5.50 seems to do wonders smoothing the "rough edges" and errors in my guesses and pushes the accuracy to high levels. http://users.better-dot-org/tfritz/site/programs/E-TESLA5.ZIP So, I don't think the voltage distribution is a sine wave. I think it looks more like a steel ruler bending under gravity in the static case or in the case of it springing back and forth as shown at: http://users.better-dot-org/tfritz/site/misc/MalRulMa/1st.jpg I would submit that your work is independently finding the same voltage profile I have found in my studies as has Malcolm. Not a sine wave at all but much more like "Malcolm's Ruler". A steel ruler, clamped in a vise at the base and pushed at the top with one's finger, appears to flex with the same profile that the voltage distributes along the secondary. Of course, I think you are the first one to figure all this out using 'real' circuit theory, T-line, lumped, etc. stuff instead of equation matching measurements (like I do). I will be very interested to see what all you have come up with. The fact that you are seeing "significantly less than a 1/4 sine wave at the start" only confirms what I have 'suspected' is the case. Perhaps that can now be proven and much better equations found!! I was looking at trying to use equations that predict a long steel spring wire bending under gravity to better refine the profile setup in E-Tesla5 but I have not gotten very far at all yet. The "C" versions and all that took priority. However, that voltage distribution is the only "loose screw" in the program. If that could be found exactly, the program would then be theoretically perfect... Cheers, Terry At 07:34 PM 6/10/00 -0400, you wrote: >Hi all and Terry in particular, > >In the process of various attempts to extract intrinsic C from various >equation for F of the secondary a related problem was giving me trouble. >ie the voltage profile on the secondary. > >The problem is that it significantly less than a 1/4 sine wave at the start. >Then I realized that the profile is dependent on whether quench has >occurred >and in the none quench case its also dependent on the current in the >primary. >So my question to Terry is during which part of the operating cycle did >you determine the profile ie pre quench or post quench or can you confirm or >deny the profile changes. > >I suspect you measured the peak voltage with no break out corresponding to >the first primary notch but the quench may have been at the next notch. > > > >Regards Bob (Robert Jones) > > > >

- Prev by Date:
**Re: E-TESLA 5.50 final...** - Next by Date:
**Re: PVC Wire for a secondary?** - Prev by thread:
**for sale - breakdown voltage tester with a nice variac inside** - Next by thread:
**Voltage profile on the secondary** - Index(es):