John Larkin's LC oscillator
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From: Baron on 12 Jun 2010 12:30 John Larkin Inscribed thus: > On Fri, 11 Jun 2010 10:38:51 -0700, Robert Baer > <robertbaer(a)localnet.com> wrote: > >>BlindBaby wrote: >>> On Fri, 11 Jun 2010 09:14:34 -0700, John Larkin >>> <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >>> >>>> On Fri, 11 Jun 2010 09:09:29 -0700, BlindBaby >>>> <BlindMelonChitlin(a)wellnevergetthatonethealbumcover.org> wrote: >>>> >>>>> On Fri, 11 Jun 2010 08:37:43 -0700, John Larkin >>>>> <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >>>>> >>>>>> On Fri, 11 Jun 2010 17:15:50 +0200, Jeroen Belleman >>>>>> <jeroen(a)nospam.please> wrote: >>>>>> >>>>>>> John Larkin wrote: >>>>>>>> I like the way it works with a very high turns ratio, very >>>>>>>> small AC drive at the emitter. But at lower ratios, it gets >>>>>>>> very nonlinear and becomes, if that means anything, a tuned >>>>>>>> blocking oscillator. The base capacitor value would be lowered >>>>>>>> so that the cap recharges a bunch during a oscillatory cycle. >>>>>>>> >>>>>>>> I'm sure JT and JF will spend the next week diligently >>>>>>>> searching for a set of values that will make my circuit not >>>>>>>> work. Then they'll crow, or rather, cluck about it. That's OK: >>>>>>>> as Woody Allen says, we need the eggs. >>>>>>> I made it squeg. Maybe that will please them. >>>>>>> >>>>>>> Jeroen Belleman >>>>>> >>>>>> Sloman is our resident squegging expert. >>>>>> >>>>>> John >>>>> >>>>> We should take a poll as to what attribute you are an expert in. >>>>> >>>>> I don't think it would result in the same determination that you >>>>> obviously think it would. >>>> Do you know what squegging means? Tell us. >>> >>> I have characterized a lot of oscillator circuits at the bench, >>> John. >>> Remember... power supplies... That was years ago. Now it is what >>> the >>> power supplies power. Still lots of oscillators though. >>> >>>> There are maybe two usages, both electronic, >>> >>> I have very little faith in your word derivative/origin >>> declarations, >>> John. That is aside from the fact that I am familiar with the word. >>> Remember? I work in this industry. >>> >>>> but one of them is >>>> obscure, >>> >>> Perhaps only in your thinking. >>> >>>> and the other is even more obscure. >>> >>> Certainly only in your thinking. >> Well, now, if both usages are NOT obscure (and i know of only one >> and >>have been a tech for at least 50 years),please TELL US the source / >>creation of the word and the context in each case. >> That way we will know that you are not just doing a fantasy trip. > > Everybody must know the less obscure case by now. > > The more obscure case: In the toob days, sometimes TV sets would have > vertical bars on the screen. It was caused by Barkhausen oscillations > in the horiz output tube, getting back into the RF input. Some TV > techs called that "squegging." > > I have no idea of the source of the word. > > John I've always thought (a burst of oscillations at regular intervals) probably from the sound made when a radio squegs. -- Best Regards: Baron.
From: krw on 12 Jun 2010 13:03 On Fri, 11 Jun 2010 16:09:17 -0700, BlindBaby <BlindMelonChitlin(a)wellnevergetthatonethealbumcover.org> wrote: >On Fri, 11 Jun 2010 16:02:58 -0700, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >>On Fri, 11 Jun 2010 15:37:52 -0700, BlindBaby >><BlindMelonChitlin(a)wellnevergetthatonethealbumcover.org> wrote: >> >>>On Sat, 12 Jun 2010 08:07:41 +1000, Grant <omg(a)grrr.id.au> wrote: >>> >>>>On Fri, 11 Jun 2010 08:16:29 -0500, John Fields <jfields(a)austininstruments.com> wrote: >>>> >>>>>On Fri, 11 Jun 2010 07:02:03 -0500, John Fields >>>>><jfields(a)austininstruments.com> wrote: >>>>> >>>>>>On 10 Jun 2010 13:23:55 -0700, Winfield Hill >>>>>><Winfield_member(a)newsguy.com> wrote: >>>>>> >>>>>> >>>>>>> In a ringing bell application, as the supply voltage sags, >>>>>>> and the amplitude drops, I imagine the circuit will move >>>>>>> from class C back to class A operation, before stopping. >>>>>> >>>>>>--- >>>>>>Why imagine? >>>>>> >>>>>>Here's a circuit list that'll show it all _and_ it'll create a .wav >>>>>>file, "bong.wav" in whatever folder the cicuit's in, so you can hear >>>>>>it. >>>>>> >>>>>>Enjoy! :-) >>>>> >>>>>--- >>>>>Oops... >>>>>Here it is: >>>> >>>>Sounds wonderful! There's so much I don't know about what LTSpice >>>>can do :( More examples that load and work as advertised, the better :) >>>> >>>>Grant. >>> >>> >>> LTSpiceIV just came out today! >>> >>>http://www.linear.com/designtools/software/switchercad.jsp >> >> >>I've been running 4.07 for a couple of weeks now. >> >>John > > > 4.07z just came out today. AlwaysWrong shifting goal posts when he's wrong, as always. You said: AlwaysWrong> LTSpiceIV just came out today! Wrong, as always.
From: Archimedes' Lever on 12 Jun 2010 14:27 On Sat, 12 Jun 2010 13:06:34 -0500, "krw(a)att.bizzzzzzzzzzzz" <krw(a)att.bizzzzzzzzzzzz> wrote: > and are still trying to cover >up by moving the goal posts. Go to the site, idiot. The release date for 4.07z was yesterday. It states so right there on their site. You lose... again... as usual.
From: krw on 12 Jun 2010 14:34 On Sat, 12 Jun 2010 11:27:30 -0700, Archimedes' Lever <OneBigLever(a)InfiniteSeries.Org> wrote: >On Sat, 12 Jun 2010 13:06:34 -0500, "krw(a)att.bizzzzzzzzzzzz" ><krw(a)att.bizzzzzzzzzzzz> wrote: > >> and are still trying to cover >>up by moving the goal posts. > > Go to the site, idiot. The release date for 4.07z was yesterday. Idiot, you said the release date for version *4* was yesterday and now you're trying to cover your stupidity with lies, a typical DimBulb move. >It states so right there on their site. It may say that but *you* didn't, DimBulb. > You lose... again... as usual. Nope. You're always wrong, AlwaysWrong.
From: John Fields on 12 Jun 2010 16:28
On Fri, 11 Jun 2010 20:04:42 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Fri, 11 Jun 2010 08:16:29 -0500, John Fields ><jfields(a)austininstruments.com> wrote: > >The .wav thing is cute. But the ringdown is being caused by the LC's >Q, not by the transistor oscillation. The R2-C4 thing dies out pretty >soon, and then the tank rings on its own. That why you need R4; at >infinite Q, it would ring forever. > >If you can get an LC with a Q that high, you can simulate a nice bell >noise by just whacking it and letting it ring... like a real brass >bell. Much simpler. --- Speaking of real world parts and more-or-less realistic bong frequencies, L1 here is a Caddell-Burns 5.6mH 2.9 ohm choke (P/N 7200-34), C1 is 10�F with an ESR of an ohm or less, and the thing oscillates at about 675Hz. Version 4 SHEET 1 936 680 WIRE -864 48 -1072 48 WIRE -800 48 -864 48 WIRE -576 48 -704 48 WIRE -448 48 -576 48 WIRE -352 48 -448 48 WIRE -448 64 -448 48 WIRE -352 64 -352 48 WIRE -864 96 -864 48 WIRE -576 96 -576 48 WIRE -928 144 -976 144 WIRE -448 160 -448 128 WIRE -352 160 -352 144 WIRE -352 160 -448 160 WIRE -976 176 -976 144 WIRE -1072 192 -1072 48 WIRE -752 192 -752 112 WIRE -752 192 -864 192 WIRE -448 192 -448 160 WIRE -576 240 -576 176 WIRE -512 240 -576 240 WIRE -864 272 -864 192 WIRE -752 272 -752 192 WIRE -976 288 -976 256 WIRE -576 304 -576 240 WIRE -448 320 -448 288 WIRE -352 320 -448 320 WIRE -448 336 -448 320 WIRE -352 336 -352 320 WIRE -1072 432 -1072 272 WIRE -976 432 -976 368 WIRE -976 432 -1072 432 WIRE -864 432 -864 352 WIRE -864 432 -976 432 WIRE -752 432 -752 336 WIRE -752 432 -864 432 WIRE -576 432 -576 368 WIRE -576 432 -752 432 WIRE -448 432 -448 416 WIRE -448 432 -576 432 WIRE -352 432 -352 416 WIRE -352 432 -448 432 WIRE -1072 528 -1072 432 FLAG -1072 528 0 SYMBOL ind2 -368 48 R0 SYMATTR InstName L1 SYMATTR Value 5.6e-3 SYMATTR Type ind SYMATTR SpiceLine Rser=2.9 SYMBOL ind2 -368 432 M180 WINDOW 0 36 80 Left 0 WINDOW 3 36 40 Left 0 SYMATTR InstName L2 SYMATTR Value 500e-6 SYMATTR Type ind SYMATTR SpiceLine Rser=.1 SYMBOL npn -512 192 R0 SYMATTR InstName Q1 SYMATTR Value 2N3904 SYMBOL res -592 80 R0 SYMATTR InstName R1 SYMATTR Value 100k SYMBOL cap -464 64 R0 SYMATTR InstName C1 SYMATTR Value 10e-6 SYMATTR SpiceLine Rser=1 SYMBOL cap -592 304 R0 SYMATTR InstName C2 SYMATTR Value 1e-7 SYMBOL voltage -1072 176 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 WINDOW 3 24 104 Invisible 0 SYMATTR Value 5 SYMATTR InstName V1 SYMBOL pnp -928 192 M180 SYMATTR InstName Q2 SYMATTR Value 2N4403 SYMBOL voltage -976 272 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 WINDOW 3 24 104 Invisible 0 SYMATTR Value PULSE(5 0 0 1e-6 1e-6 .01) SYMATTR InstName V3 SYMBOL npn -800 112 R270 SYMATTR InstName Q3 SYMATTR Value 2N3904 SYMBOL cap -768 272 R0 SYMATTR InstName C3 SYMATTR Value 7.5e-6 SYMBOL res -880 256 R0 SYMATTR InstName R2 SYMATTR Value 2e6 SYMBOL res -992 160 R0 SYMATTR InstName R3 SYMATTR Value 1000 SYMBOL res -464 320 R0 SYMATTR InstName R4 SYMATTR Value 1000 TEXT -432 184 Left 0 !K1 L1 L2 1 TEXT -1048 464 Left 0 !.tran 2.5 uic TEXT -1048 496 Left 0 !.wave .\\bong.wav 8 10000 N008 JF |