[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [TCML] voltage
While I commend your enthusism, I really don't think building a large voltage divider is really practical. Practically speaking, its going to be huge! I've designed many wide-bandwidth high voltage dividers in my career and even the small ones are really big.
Here is a 60kV, 50MHz divider I designed and built to use with primary coil measurements.
http://www.easternvoltageresearch.com/resources/60kvdivider_fullschematic.pdf
This divider alone is about a foot high. I can't imagine how large one would be to measure the secondary voltage. Also, the loading of the divider itself on the secondary would likely affect measurements.
So far, the best quantitative way I've seen to indirectly measure secondary voltage is via Terry Fritz's Antenna Probe. That works great, is small, low cost, and works extremely well.
No need to make something more complicated than it needs to be.
Dan
http://www.easternvoltageresearch.com
-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf Of Carl Noggle
Sent: Thursday, January 26, 2012 9:47 AM
To: Tesla Coil Mailing List
Subject: EXTERNAL: Re: [TCML] voltage
Me too. That's a really good idea. If we make the divider with parallel R and C sections, with good design we should have high enough bandwidth to make good measurements. The division ratio of the R divider should equal the ratio of the R section. If somebody has access to a bunch of old Allen-Bradley 2W carbon comp resistors, it would be a pretty straightforward build. Say, 100 10M resistors paralleled by 100 50pF 5kV ceramic caps, with a bottom stage of 1M parallel 500pF for a
1000/1 divider. Should even work as a probe for a high impedance scope input. It would be better to have the bottom resistor user-changeable to match different meters, etc.
---Carl
> This actually sounds like a moderately good idea. But we should go about it in a slightly more scientific way.
>
> I would be willing to bet that with the combined efforts of some list members, we can produce a "box" that contains the stuff needed and instructions on how to accurately measure the voltage of a particular coil. Pass the box around, and in a few months we should have tons of data. Data which could be correlated based on coil input power, physical characteristics of coils, frequency of operation etc. Match that data up with a maximum spark length each particular coil could produce. and we should now have a pretty close model of voltage to spark length characteristics . maybe some fancy graphs to show the world.
>
> This would require team work, I for one would be up to participate. =)
>
>
>
>
>
>
> I mentioned this earlier, but i don't see why a huge voltage divider would not work, since we all seem to be interested in spark lengths relation to voltage.
> tons of resistors, in a wax or epoxy filled pvc pipe, mini toroid on top, a little tripod to set it up. Ground one end let the farthest spark hit the other, rectify and filter the last resistor and measure the peak voltage. I have done something similar before with my mini coil a long time ago, way long ago, before i really even knew how to make an actual coil.
>
>
>
> Thanks,
> John "Jay" Howson IV
>
>
> "Why thank you, I will be happy to take those electrons off your hands."
>
> ----- Original Message -----
> From: "Bob Svangren"<qogman@xxxxxxxxxxx>
> Sent: Wednesday, January 25, 2012 1:04:54 PM
> Subject: [TCML] voltage
>
>
> Hi guys,
> I notice that there is a lot of conversation on measuring the terminal voltages on these fantastic coils.
> I have read a lot of books on the subject over the years and found that it takes very complicated and costly equipment to measure these very high voltages. It seems that everything has a bearing on the accurate measurements such as the electrostatic field, barometric pressure, humidity, AC- DC. frequency and many other factors.
> Of course we all like boasting rights of our coil output and it's
> great to say that we are putting out a million volts but in reality, no one is sure of this number The best experts cant agree on what an inch of arc is equal too but it ranges from 10,000 volts per inch to 50,000 volts per inch of arc. The makers of stun guns claim anywhere from 100,000 volts to a million volts for less than a three inch arc as one example. Who would believe any of this to be fact.
> We do need our boasting rights and I for one would be in favor of adopting our own voltage standard which we could all understand and would do away with all this guess work.
> I have determined that 20,000 volts would be a good and close to accurate standard for us to use and we would all be on the same page. Be it right or be it wrong the 20KV per inch should be close for our use.
> If we should adopt the 20KV volts per inch standard, I would be in favor of naming our new standard after the late and great Mr. Harry Goldman who gave much of his life to making coiling fun and interesting for all of us to enjoy. We could simply call this the Goldman standard. A 50 inch arc would equal a million volts. Doesn't that have a nice ring to it?
> So, the big question is, what do you fellows think of this plan.
> Bob _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla