| Coil Losses (Terry's Energy Balance of a TC) | |||||||||||
| To: tesla@pupman.com | |||||||||||
| Subject: Re: coil losses | |||||||||||
| From: "Malcolm Watts" <malcolm.watts@wnp.ac.nz> (by way of Terry Fritz <twftesla@uswest.net>) | |||||||||||
| Date: Mon, 14 Jun 1999 18:29:21 -0600 | |||||||||||
| Hi Terry, | |||||||||||
| > Original Poster: Terry Fritz <twftesla@uswest.net> | |||||||||||
| > | |||||||||||
| > At 09:06 AM 6/14/99 +1200, "Malcolm Watts" <malcolm.watts@wnp.ac.nz> wrote: | |||||||||||
| > >Hi Terry, | |||||||||||
| > > Great post: | |||||||||||
| > > | |||||||||||
| > >> Original Poster: Terry Fritz <twftesla@uswest.net> | |||||||||||
| > >> | |||||||||||
| > >> Hi All, | |||||||||||
| > >> | |||||||||||
| > >> Here is a list of the losses in a Tesla coil I had laying around. I | B&W TC | ||||||||||
| > >> forget the details but the numbers should be fairly typical. I think this | if same % | ||||||||||
| > >> is an LTR design... | energy | ||||||||||
| > >> | Terry's Test TC | distribution | |||||||||
| > >> | Watts | % | Watts | ||||||||
| > >> Primary Neon Windings | 29 | 3,74% | 321 | ||||||||
| > >> Secondary Neon Windings | 21 | 2,71% | 232 | ||||||||
| > >> Filter Resistors | 92 | 11,86% | 1017 | ||||||||
| > >> Primary Circuit Loss | 490 | 63,14% | 5418 | *) | |||||||
| > >> Secondary Circuit Loss | 17 | 2,19% | 188 | ||||||||
| > >> Power to Arc | 127 | 16,37% | 1404 | ||||||||
| > >> Total | 776 | 100,00% | 8581 | ||||||||
| > >> | |||||||||||
| > >> Note that almost half the coil's energy is being burned up in the gap. | *) not very plausible in my case, 'cause | ||||||||||
| > >> Capacitor losses and primary coil losses are comparatively low so the gap | the SRSG electrodes getting barely | ||||||||||
| > >> is eating power like mad... | handwarm at ~11kVA input power. | ||||||||||
| > >> | With 3000 RPM / BPS = 200 | ||||||||||
| > >> Terry | (4 stationary / 2 rotating electrodes) | ||||||||||
| > > | |||||||||||
| > >I realized this early on by considering the noise, light and heat in | |||||||||||
| > >the gap. BTW, a gap that is loud compared to the secondary discharge | |||||||||||
| > >means something can be done to considerably improve output at the | |||||||||||
| > >same power level. | |||||||||||
| > > | |||||||||||
| > >Regards, | |||||||||||
| > >Malcolm | |||||||||||
| > > | |||||||||||
| > | |||||||||||
| > Hi Malcolm, | |||||||||||
| > | |||||||||||
| > The terrible gap losses can be significantly reduced by good quenching | |||||||||||
| > trapping the primary energy in the secondary system so that it cannot be | |||||||||||
| > chewed up in the wasteful gap. Of course, good quenching is much more | |||||||||||
| > easily said than done. | |||||||||||
| Every attempt I've made at forcing a good quench suggests to me that | |||||||||||
| it is achieved with higher wasteful primary losses. Better to achieve | |||||||||||
| it with a strong output. | |||||||||||
| > I would like to try a series gap like the ones I made from copper pipe | |||||||||||
| > sections in series with a rotary next. Rotaries tend to be poor quenchers | |||||||||||
| > despite their other favorable characteristics. Even timing critical LTR | |||||||||||
| > systems can support additional series gaps since the rotary still controls | |||||||||||
| > the timing. | |||||||||||
| > | |||||||||||
| > Backing off the coupling seems to help quenching too without a great | |||||||||||
| > effect on energy throughput. With lower coupling, it just takes a bit | |||||||||||
| > longer to transfer the energy to the secondary. However, if lower coupling | |||||||||||
| > allowed better quenching, the small energy loss caused by lower coupling | |||||||||||
| > would be far outweighed by the advantages of good quenching. | |||||||||||
| > | |||||||||||
| > Cheers, | |||||||||||
| > | |||||||||||
| > Terry | |||||||||||
| Just re-reading that original post makes me think you are running the | |||||||||||
| coil with air streamers. Yes? Transfer efficiencies can easily beat | |||||||||||
| the 80% mark so the implication is that there are multiple energy | |||||||||||
| trades going on in this coil which implies minimal output loading. | |||||||||||
| That result is to be expected for air streamers but is very poor for | |||||||||||
| attached discharges. | |||||||||||
| Agree with the comment about backing off the coupling. It does | |||||||||||
| give the gap a quiet time for longer between trades and the loss is | |||||||||||
| really quite minimal. It might also give the secondary a better | |||||||||||
| chance to lose energy on earlier trades as it prolongs secondary ring | |||||||||||
| time per trade. | |||||||||||
| Cheers, | |||||||||||
| Malcolm | |||||||||||
| Date: Sat, 07 Oct 2000 18:50:47 -0600 | B&W TC | ||||||||||
| From: "Terry Fritz" <terrellf@uswest.net> | if same % | ||||||||||
| Sender: owner-tssp@abelian.demon.co.uk | energy | ||||||||||
| To: tssp@abelian.demon.co.uk | distribution | ||||||||||
| Watts | Percent | Watts | |||||||||
| Power into coil | 840 | 100 | 8581 | ||||||||
| Power in 50 foot cable | 15,88 | 1,89 | 162 | ||||||||
| Power in neon primary | 30,47 | 3,63 | 311 | ||||||||
| Power in neon secondary | 38,2 | 4,55 | 390 | ||||||||
| Power in NST filter | 96,4 | 11,48 | 985 | ||||||||
| Power in gap | 156 | 18,57 | 1593 | ||||||||
| Power in primary cap | (7.5C temp rise) | 9,354 | 1,11 | 95 | |||||||
| Power in primary coil | 76,08 | 9,06 | 777 | ||||||||
| Power in secondary coil | 71,84 | 8,55 | 734 | ||||||||
| Power in self capacitance | 14,95 | 1,78 | 153 | ||||||||
| Power in terminal capacitance | 8,49 | 1,01 | 87 | ||||||||
| Power to arc | 322 | 38,33 | 3289 | ||||||||
| TOTAL | 839,66 | 99,96 | 8578 | ||||||||
| These models are improved over time as are the coils, so the numbers are a | |||||||||||
| bit different... | |||||||||||