LTSpice is impossible to work with, it's just one glitch after another, after another, after another...That's not my experience, nor John Larkin's either.
Your experience with the kluge is too slight to make your opinion of notable value.
On Thursday, December 21, 2023 at 8:40:45?AM UTC-5, John Larkin wrote:wasn't. The Help files are full of bs terminology to make things sound more technical than they really are.
On Thu, 21 Dec 2023 04:12:57 -0800 (PST), Fred Bloggs
<bloggs.fred...@gmail.com> wrote:
LT Spice is wonderful. I didn't find it at all hard to learn, and its
LTSpice is impossible to work with, it's just one glitch after another, after another, after another...That's not my experience, nor John Larkin's either.
Your experience with the kluge is too slight to make your opinion of notable value.
quirks are few. The Help could be better, but there's tons of help
online. Mike claims it has 1000x the use of any other circuit
simulator. And it's free.
There are too many glitches all over the place, lots of little tiny things that ruin everything. I can't even run a dumb DC transfer on my circuit. It keeps giving me some kind of fatal error message about source(null) not in the circuit. The hell if it
You're welcome to try it yourself, let me know how it turns out:
Version 4
SHEET 1 880 724
WIRE -1104 -32 -1104 -64
WIRE -800 -32 -800 -80
WIRE -1376 -16 -1376 -32
WIRE -1760 0 -1808 0
WIRE -1552 0 -1680 0
WIRE -1408 0 -1552 0
WIRE -1280 16 -1280 -16
WIRE -1280 16 -1344 16
WIRE -1200 16 -1280 16
WIRE -1168 16 -1200 16
WIRE -1552 32 -1552 0
WIRE -1408 32 -1472 32
WIRE -1200 32 -1200 16
WIRE -1376 80 -1376 48
WIRE -1472 128 -1472 32
WIRE -1344 128 -1472 128
WIRE -1104 128 -1104 64
WIRE -1104 128 -1264 128
WIRE -1552 160 -1552 112
WIRE -1104 160 -1104 128
WIRE -1472 192 -1472 128
WIRE -1200 192 -1200 96
WIRE -1200 192 -1472 192
WIRE -1904 272 -1904 256
WIRE -1904 272 -1968 272
WIRE -1808 272 -1808 0
WIRE -1808 272 -1904 272
WIRE -1552 272 -1552 240
WIRE -1552 272 -1808 272
WIRE -1104 272 -1104 240
WIRE -960 272 -1104 272
WIRE -800 272 -800 48
WIRE -640 272 -800 272
WIRE -960 288 -960 272
WIRE -912 288 -960 288
WIRE -1968 304 -1968 272
WIRE -1552 304 -1552 272
WIRE -1104 304 -1104 272
WIRE -960 320 -960 288
WIRE -640 320 -640 272
WIRE -1200 352 -1472 352
WIRE -1552 416 -1552 384
WIRE -1472 416 -1472 352
WIRE -1344 416 -1472 416
WIRE -1104 416 -1104 384
WIRE -1104 416 -1264 416
WIRE -1968 432 -1968 384
WIRE -1200 448 -1200 352
WIRE -960 448 -960 400
WIRE -1104 480 -1104 416
WIRE -1376 496 -1376 464
WIRE -800 496 -800 272
WIRE -1472 512 -1472 416
WIRE -1408 512 -1472 512
WIRE -1248 528 -1344 528
WIRE -1200 528 -1200 512
WIRE -1200 528 -1248 528
WIRE -1168 528 -1200 528
WIRE -1808 544 -1808 272
WIRE -1760 544 -1808 544
WIRE -1552 544 -1552 496
WIRE -1552 544 -1680 544
WIRE -1408 544 -1552 544
WIRE -1248 560 -1248 528
WIRE -1376 576 -1376 560
WIRE -1104 608 -1104 576
WIRE -800 624 -800 576
FLAG -1968 432 0
FLAG -960 448 0
FLAG -1376 -32 V-
FLAG -1376 576 V-
FLAG -1376 80 V+
FLAG -912 288 Vout
FLAG -1904 256 Vin
FLAG -640 320 0
FLAG -800 -80 V+
FLAG -800 624 V-
FLAG -1280 -16 VB1
FLAG -1248 560 VB2
FLAG -1376 464 V+
FLAG -1104 -64 V+
FLAG -1104 608 V-
DATAFLAG -1728 272 ""
SYMBOL res -1120 144 R0
SYMATTR InstName R1
SYMATTR Value 0.33
SYMBOL res -1120 288 R0
SYMATTR InstName R2
SYMATTR Value 0.33
SYMBOL res -1248 400 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R3
SYMATTR Value 1k
SYMBOL res -1248 112 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R4
SYMATTR Value 1k
SYMBOL res -1664 -16 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R5
SYMATTR Value 1k
SYMBOL res -1568 16 R0
SYMATTR InstName R6
SYMATTR Value 99k
SYMBOL res -1568 400 R0
SYMATTR InstName R7
SYMATTR Value 99k
SYMBOL res -1664 528 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R8
SYMATTR Value 1k
SYMBOL voltage -1552 144 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 3.3
SYMBOL voltage -1552 288 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value 3.3
SYMBOL voltage -1968 288 R0
WINDOW 3 24 44 Left 2
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR Value SINE(0 5 10k 0 0 0 2)
SYMATTR InstName V3
SYMBOL res -976 304 R0
SYMATTR InstName R9
SYMATTR Value 4
SYMBOL voltage -800 -48 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V4
SYMATTR Value 7
SYMBOL voltage -800 480 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V5
SYMATTR Value 7
SYMBOL Opamps\\UniversalOpAmp1 -1376 16 M180
WINDOW 0 19 34 Left 2
SYMATTR InstName U3
SYMBOL Opamps\\UniversalOpAmp1 -1376 528 R0
SYMATTR InstName U4
SYMBOL pnp -1168 576 M180
SYMATTR InstName Q1
SYMBOL npn -1168 -32 R0
SYMATTR InstName Q2
SYMBOL diode -1184 512 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D1
SYMBOL diode -1184 96 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D2
TEXT -2000 696 Left 2 !;op V3 -5 5 0.01
TEXT -2072 496 Left 2 !;dc V3 -.5 .5 .01
TEXT -2064 536 Left 2 !.tran 0 200u 0
TEXT -2096 600 Left 2 !;tf Vout V3
I take it if you remove that phony comment "!" symbol on the sim directive, the thing will run that sim?
Anyway, the circuit, using ideal library components, is proof of principle that making the voltages follow and using minuscule offsets eliminates crossover. This is because both transistors are forward biased and conducting in the vicinity of 0V input (+/-1V), and the transistor following its polarity of the input has to be conducting substantially to reverse bias the transistor going into the off state. There's nothing discontinuous visible on the transient graphs. But then all the components are ideal.
Circuit is a circuit block intended to be inside the feedback loop of an input buffer or gain element.
What do you use for circuit simulation?
If it has to be simulated, I'm not interested in it.
On Thu, 21 Dec 2023 18:49:15 -0800 (PST), Fred Bloggs <bloggs.fredbloggs.fred@gmail.com> wrote:
On Thursday, December 21, 2023 at 8:40:45?AM UTC-5, John Larkin wrote:<snip>
On Thu, 21 Dec 2023 04:12:57 -0800 (PST), Fred Bloggs
<bloggs.fred...@gmail.com> wrote:
LT Spice is wonderful. I didn't find it at all hard to learn, and its
LTSpice is impossible to work with, it's just one glitch afterThat's not my experience, nor John Larkin's either.
another, after another, after another...
Your experience with the kluge is too slight to make your opinion of notable value.
quirks are few. The Help could be better, but there's tons of help
online. Mike claims it has 1000x the use of any other circuit
simulator. And it's free.
There are too many glitches all over the place, lots of little tiny
things that ruin everything. I can't even run a dumb DC transfer on my
circuit. It keeps giving me some kind of fatal error message about
source(null) not in the circuit. The hell if it wasn't. The Help files
are full of bs terminology to make things sound more technical than they really are.
You're welcome to try it yourself, let me know how it turns out:
Version 4
I take it if you remove that phony comment "!" symbol on the sim
directive, the thing will run that sim?
It seems to run fine. Is there a problem?
On Thu, 21 Dec 2023 04:12:57 -0800 (PST), Fred Bloggs <bloggs.fredbloggs.fred@gmail.com> wrote:
LTSpice is impossible to work with, it's just one glitch afterThat's not my experience, nor John Larkin's either.
another, after another, after another...
Your experience with the kluge is too slight to make your opinion of notable value.
LT Spice is wonderful. I didn't find it at all hard to learn, and its
quirks are few. The Help could be better, but there's tons of help
online. Mike claims it has 1000x the use of any other circuit
simulator. And it's free.
What do you use for circuit simulation?
I've been using LT as a graphing calculator. A BV block can crunch
most any equation. Using a bunch of BVs breaks a complex expression
into components, so a click can graph intermediate terms, which adds
insight. And you can even include electronic components!
LT can be used for manual illustrations too. That's really easier than
Visio or whatever. What do you use for figures in manuals?
John Larkin <jl@997PotHill.com> wrote:
On Thu, 21 Dec 2023 04:12:57 -0800 (PST), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:
LTSpice is impossible to work with, it's just one glitch afterThat's not my experience, nor John Larkin's either.
another, after another, after another...
Your experience with the kluge is too slight to make your opinion of notable value.
LT Spice is wonderful. I didn't find it at all hard to learn, and its
quirks are few. The Help could be better, but there's tons of help
online. Mike claims it has 1000x the use of any other circuit
simulator. And it's free.
What do you use for circuit simulation?
I've been using LT as a graphing calculator. A BV block can crunch
most any equation. Using a bunch of BVs breaks a complex expression
into components, so a click can graph intermediate terms, which adds
insight. And you can even include electronic components!
LT can be used for manual illustrations too. That's really easier than
Visio or whatever. What do you use for figures in manuals?
The other annoying thing about LTspice is the part selection dialogues.
Its a missed opportunity for ADwhen you scroll through the list of op
amps, say, theres no way to tell which ones are good for what, or to
filter or sort them.
Bad Medicine.
Cheers
Phil Hobbs
On Fri, 22 Dec 2023 14:30:24 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
John Larkin <jl@997PotHill.com> wrote:
On Thu, 21 Dec 2023 04:12:57 -0800 (PST), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:
LTSpice is impossible to work with, it's just one glitch afterThat's not my experience, nor John Larkin's either.
another, after another, after another...
Your experience with the kluge is too slight to make your opinion of notable value.
LT Spice is wonderful. I didn't find it at all hard to learn, and its
quirks are few. The Help could be better, but there's tons of help
online. Mike claims it has 1000x the use of any other circuit
simulator. And it's free.
What do you use for circuit simulation?
I've been using LT as a graphing calculator. A BV block can crunch
most any equation. Using a bunch of BVs breaks a complex expression
into components, so a click can graph intermediate terms, which adds
insight. And you can even include electronic components!
LT can be used for manual illustrations too. That's really easier than
Visio or whatever. What do you use for figures in manuals?
The other annoying thing about LTspice is the part selection dialogues.
Its a missed opportunity for ADwhen you scroll through the list of op
amps, say, theres no way to tell which ones are good for what, or to
filter or sort them.
Bad Medicine.
Cheers
Phil Hobbs
I agree there. Why don't they pop up brief specs and data sheets?
I mostly use Universal Opamp 2 and tweak the bw and slew rates.
But generally, parts selection is a mess, with a dozen semi companies introducing thousands of new parts every year.
John Larkin <jl@997PotHill.com> wrote:
On Fri, 22 Dec 2023 14:30:24 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
John Larkin <jl@997PotHill.com> wrote:
On Thu, 21 Dec 2023 04:12:57 -0800 (PST), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:
The other annoying thing about LTspice is the part selection dialogues.
Its a missed opportunity for ADwhen you scroll through the list of op >>> amps, say, theres no way to tell which ones are good for what, or to
filter or sort them.
I agree there. Why don't they pop up brief specs and data sheets?
I mostly use Universal Opamp 2 and tweak the bw and slew rates.
Me too. Op amp models are mostly terrible anyway.
But generally, parts selection is a mess, with a dozen semi companies
introducing thousands of new parts every year.
You say that like it’s a bad thing. ;)
On 23/12/2023 4:25 am, Phil Hobbs wrote:
John Larkin <jl@997PotHill.com> wrote:
On Fri, 22 Dec 2023 14:30:24 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Me too. Op amp models are mostly terrible anyway.
And they won't get any better if people don't use them and complain
about their defects. Jim Thompson tried to get manufactures to pay him
to set up more realistic models, but his personality may have got in the
way.
It's the free market doing exactly what it is supposed to. Admittedly,
most of they new parts are me-too versions of other people's parts,
but Linear Technology made a business to taking other people's new parts
and making them better that the originals.
And AD took Linear Technology's LT1028 and trumped it with the AD797, at
a rather higher price.
On Sat, 23 Dec 2023 19:45:51 -0800 (PST), Anthony William Sloman <bill.sloman@ieee.org> wrote:transistor model is supposed to model inverted operation better, but the model parameters are treated as commercial-in-confidence by the semiconductor companies. I've mentioned this here before, and never been able get anybody to send me even a single
On Sunday, December 24, 2023 at 8:15:42?AM UTC+11, Fred Bloggs wrote:
On Thursday, December 21, 2023 at 11:49:01?PM UTC-5, Anthony William Sloman wrote:
On Friday, December 22, 2023 at 1:56:14?PM UTC+11, Fred Bloggs wrote: >>>>> On Thursday, December 21, 2023 at 8:40:17?AM UTC-5, Anthony William Sloman wrote:
<snip>On Thursday, December 21, 2023 at 11:13:03?PM UTC+11, Fred Bloggs wrote: >>>>>>> On Wednesday, December 20, 2023 at 11:45:54?PM UTC-5, Anthony William Sloman wrote:
On Thursday, December 21, 2023 at 12:43:01?AM UTC+11, Fred Bloggs wrote:
I'd scarcely be able to read your posts if I had.Something has impaired you terribly. Maybe you went blind?More of your broad based slander devoid of any detail or justification, a symptom of your rapid decline of mental health, or conversely an acceleration of mental ill-health.
Wrong.'
<snip>LTSpice is impossible to work with, it's just one glitch after another, after another, after another...
That's not my experience, nor John Larkin's either.
Your experience with the kluge is too slight to make your opinion of notable value.
I've been posting .asc's for at least ten years.
I suppose it would be too much to ask for a speaker 'component' which will play the simulation outcome through a sound system, or the ability to supply a music file for the circuit to process.
Why would they go to that sort of trouble?
I'm not.The whole point of audio design is to minimise the non-linearities and prevent the mixing - and two tone signals test that perfectly adequately.Okay- you use 'blindingly'. Maybe you are blind then.
The P.O.S. gives the right output in DC sweep, but the opamp nodes explode out of sight with kV voltages. As for transient- just forget it- the whole thing is garbage.
The basic concept is silly. Why complain when a useless circuit give useless results.
You don't know anything about the subject matter.
That circuit made it blindingly obvious that you don't.
CAD can inform bench work, and you can certainly compare simulated results with actual results.You can simulate a transistor level audio amplifier in LTSpice, and get plausible results. Why futz around with universal op amps and unspecified transitors?
In case you haven't noticed, that type of component exists in their component library because of its value in simplification of circuit development through simulation. But again, you wouldn't know anything about that.
It's a great deal more helpful to simulate real components. I had a run-in with John Fields about that about a low-current 100kHz oscillator about ten years ago.
Like John Larkin he didn't bother adding parallel capacitance to his inductor, and when I ran his simulation with a real inductor you could buy off the shelf it didn't work, and took quite a bit of tinkering to make it work.
There's CAD work and then there's bench work. You can't do both at the same time.
Simulation can let you get deeper into a simulated circuit than your instruments can get you into a working circuit.
The end result should be a better comprehension of what is actually going on.
It doesn't always work. Simulating a Baxandall class-D oscillator built with bipolar transistors can't reproduce the "squegging" you see in real life if you use too big a feed inductor, or a least not with the Gummel-Poon transistor model. The VBIC
AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper “Transistors as on-off switches in saturable core circuitsShould be something you can measure on the bench.
https://designers-guide.org/vbic/
What is the significance of the Baxandall oscillator? Can it be used for anything?
From my web-site - http://sophia-elektronica.com/Baxandall_parallel-resonant_Class-D_oscillator1.htm
" The circuit is probably best known from Jim Williams’ series of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61,
group sci.electroncs.design Wed, Oct 1 2003 5:35 pm) and always produces a slightly non-sinusoidal output."
As Jim Williams points out, this circuit can offer good efficiency – 90% - when driving difficult loads. It is a rather cranky circuit, which works best if of the resonant tank has a Q of between 5 and 10 – according to Tony Williams (on the user
photomultiplier power supply generating 1kV or more from a 12V supply.,
It's particular virtue is that it copes with high parallel capacitance you get in the kind of high-turns ratio step-up transformers that you need when generating high voltages. Peter Baxandall seems to have invented it when he needed a compact
Your LTSpice .asc file at http://sophia-elektronica.com/Classic_Baxandall_Class-D.htm
seems to be badly broken
You are unlikely to find VBIC models of discretes anywhere, your best
bet is running a SGP model through the sgp2vbic perl script and then tweaking. There's a starting point for a 3904 VBIC model (not created
or checked by by me) in the attached LTSpice asc listing. I've tried
it in a npn version of figure 10 of Mr Baxandall's paper but LTSpice
does not handle it properly (I haven't bothered to look to see which
VBIC parameters LTSpice supports). It does however work in the
Simetrix simulator, and probably will in ngspice. NXP might give you
level 50x (Mextram) models under NDA.
I seem to recall that they used
to give a some examples in their compact model interface simkit, but I downloaded the latest one just now and they seem to have been removed.
On Monday, December 25, 2023 at 6:57:59?AM UTC-5, Anthony William Sloman wrote:VBIC transistor model is supposed to model inverted operation better, but the model parameters are treated as commercial-in-confidence by the semiconductor companies. I've mentioned this here before, and never been able get anybody to send me even a
On Monday, December 25, 2023 at 6:39:40?AM UTC+11, Fred Bloggs wrote:
On Saturday, December 23, 2023 at 10:45:56?PM UTC-5, Anthony William Sloman wrote:
On Sunday, December 24, 2023 at 8:15:42?AM UTC+11, Fred Bloggs wrote:
On Thursday, December 21, 2023 at 11:49:01?PM UTC-5, Anthony William Sloman wrote:
On Friday, December 22, 2023 at 1:56:14?PM UTC+11, Fred Bloggs wrote:
On Thursday, December 21, 2023 at 8:40:17?AM UTC-5, Anthony William Sloman wrote:<snip>
On Thursday, December 21, 2023 at 11:13:03?PM UTC+11, Fred Bloggs wrote:
On Wednesday, December 20, 2023 at 11:45:54?PM UTC-5, Anthony William Sloman wrote:
On Thursday, December 21, 2023 at 12:43:01?AM UTC+11, Fred Bloggs wrote:
I'd scarcely be able to read your posts if I had.Something has impaired you terribly. Maybe you went blind?More of your broad based slander devoid of any detail or justification, a symptom of your rapid decline of mental health, or conversely an acceleration of mental ill-health.
Wrong.'
<snip>LTSpice is impossible to work with, it's just one glitch after another, after another, after another...
That's not my experience, nor John Larkin's either.
Your experience with the kluge is too slight to make your opinion of notable value.
I've been posting .asc's for at least ten years.
I suppose it would be too much to ask for a speaker 'component' which will play the simulation outcome through a sound system, or the ability to supply a music file for the circuit to process.
Why would they go to that sort of trouble?
I'm not.The whole point of audio design is to minimise the non-linearities and prevent the mixing - and two tone signals test that perfectly adequately.Okay- you use 'blindingly'. Maybe you are blind then.
The P.O.S. gives the right output in DC sweep, but the opamp nodes explode out of sight with kV voltages. As for transient- just forget it- the whole thing is garbage.
The basic concept is silly. Why complain when a useless circuit give useless results.
You don't know anything about the subject matter.
That circuit made it blindingly obvious that you don't.
CAD can inform bench work, and you can certainly compare simulated results with actual results.You can simulate a transistor level audio amplifier in LTSpice, and get plausible results. Why futz around with universal op amps and unspecified transitors?
In case you haven't noticed, that type of component exists in their component library because of its value in simplification of circuit development through simulation. But again, you wouldn't know anything about that.
It's a great deal more helpful to simulate real components. I had a run-in with John Fields about that about a low-current 100kHz oscillator about ten years ago.
Like John Larkin he didn't bother adding parallel capacitance to his inductor, and when I ran his simulation with a real inductor you could buy off the shelf it didn't work, and took quite a bit of tinkering to make it work.
There's CAD work and then there's bench work. You can't do both at the same time.
Simulation can let you get deeper into a simulated circuit than your instruments can get you into a working circuit.
The end result should be a better comprehension of what is actually going on.
It doesn't always work. Simulating a Baxandall class-D oscillator built with bipolar transistors can't reproduce the "squegging" you see in real life if you use too big a feed inductor, or a least not with the Gummel-Poon transistor model. The
AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper Transistors as on-off switches in saturable core circuits inShould be something you can measure on the bench.From my web-site - http://sophia-elektronica.com/Baxandall_parallel-resonant_Class-D_oscillator1.htm
https://designers-guide.org/vbic/
What is the significance of the Baxandall oscillator? Can it be used for anything?
" The circuit is probably best known from Jim Williams series of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61,
group sci.electroncs.design Wed, Oct 1 2003 5:35 pm) and always produces a slightly non-sinusoidal output."
As Jim Williams points out, this circuit can offer good efficiency 90% - when driving difficult loads. It is a rather cranky circuit, which works best if of the resonant tank has a Q of between 5 and 10 according to Tony Williams (on the user
photomultiplier power supply generating 1kV or more from a 12V supply.
It's particular virtue is that it copes with high parallel capacitance you get in the kind of high-turns ratio step-up transformers that you need when generating high voltages. Peter Baxandall seems to have invented it when he needed a compact
decades, and may no longer be relevant.
From what I can see that CCFL stuff has been beaten to death by the lightbulb industry. They don't even use a transformer, they use a resonant LC driven by an off-the-line half bridge switch. The JW, and certainly Baxandall, predates all that by 4-5
large screen displays.Cold cathode lamps don't seem to be used any more. Lap-tops rely on arrays of multiplexed light-emitting diodes for their displays - I think organic LEDS dominate that market now, but it's been a while since I paid much attention to the mechanics of
The LC resonant serves a dual mode of resonating to strike the initial arc and then relaxing to form a simple ballast for the load.
Cold cathode lamps rely on a glow discharge, not an arc, as you'd be a aware if you knew anything about the subject. The very name "cold cathode lamp" would have told you about that if you had the barest minimum of background knowledge.
Not interested in that kind of detail...could care less.
On Mon, 25 Dec 2023 05:39:53 -0800 (PST), Fred Bloggs <bloggs.fredbloggs.fred@gmail.com> wrote:VBIC transistor model is supposed to model inverted operation better, but the model parameters are treated as commercial-in-confidence by the semiconductor companies. I've mentioned this here before, and never been able get anybody to send me even a
On Monday, December 25, 2023 at 6:57:59?AM UTC-5, Anthony William Sloman wrote:
On Monday, December 25, 2023 at 6:39:40?AM UTC+11, Fred Bloggs wrote:
On Saturday, December 23, 2023 at 10:45:56?PM UTC-5, Anthony William Sloman wrote:
On Sunday, December 24, 2023 at 8:15:42?AM UTC+11, Fred Bloggs wrote: >>>>>> On Thursday, December 21, 2023 at 11:49:01?PM UTC-5, Anthony William Sloman wrote:
On Friday, December 22, 2023 at 1:56:14?PM UTC+11, Fred Bloggs wrote: >>>>>>>> On Thursday, December 21, 2023 at 8:40:17?AM UTC-5, Anthony William Sloman wrote:
<snip>On Thursday, December 21, 2023 at 11:13:03?PM UTC+11, Fred Bloggs wrote:
On Wednesday, December 20, 2023 at 11:45:54?PM UTC-5, Anthony William Sloman wrote:
On Thursday, December 21, 2023 at 12:43:01?AM UTC+11, Fred Bloggs wrote:
I'd scarcely be able to read your posts if I had.Something has impaired you terribly. Maybe you went blind?More of your broad based slander devoid of any detail or justification, a symptom of your rapid decline of mental health, or conversely an acceleration of mental ill-health.
Wrong.'
<snip>LTSpice is impossible to work with, it's just one glitch after another, after another, after another...
That's not my experience, nor John Larkin's either.
Your experience with the kluge is too slight to make your opinion of notable value.
I've been posting .asc's for at least ten years.
I suppose it would be too much to ask for a speaker 'component' which will play the simulation outcome through a sound system, or the ability to supply a music file for the circuit to process.
Why would they go to that sort of trouble?
I'm not.The whole point of audio design is to minimise the non-linearities and prevent the mixing - and two tone signals test that perfectly adequately.Okay- you use 'blindingly'. Maybe you are blind then.
The P.O.S. gives the right output in DC sweep, but the opamp nodes explode out of sight with kV voltages. As for transient- just forget it- the whole thing is garbage.
The basic concept is silly. Why complain when a useless circuit give useless results.
You don't know anything about the subject matter.
That circuit made it blindingly obvious that you don't.
CAD can inform bench work, and you can certainly compare simulated results with actual results.You can simulate a transistor level audio amplifier in LTSpice, and get plausible results. Why futz around with universal op amps and unspecified transitors?
In case you haven't noticed, that type of component exists in their component library because of its value in simplification of circuit development through simulation. But again, you wouldn't know anything about that.
It's a great deal more helpful to simulate real components. I had a run-in with John Fields about that about a low-current 100kHz oscillator about ten years ago.
Like John Larkin he didn't bother adding parallel capacitance to his inductor, and when I ran his simulation with a real inductor you could buy off the shelf it didn't work, and took quite a bit of tinkering to make it work.
There's CAD work and then there's bench work. You can't do both at the same time.
Simulation can let you get deeper into a simulated circuit than your instruments can get you into a working circuit.
The end result should be a better comprehension of what is actually going on.
It doesn't always work. Simulating a Baxandall class-D oscillator built with bipolar transistors can't reproduce the "squegging" you see in real life if you use too big a feed inductor, or a least not with the Gummel-Poon transistor model. The
AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper “Transistors as on-off switches in saturable core circuits”Should be something you can measure on the bench.From my web-site - http://sophia-elektronica.com/Baxandall_parallel-resonant_Class-D_oscillator1.htm
https://designers-guide.org/vbic/
What is the significance of the Baxandall oscillator? Can it be used for anything?
" The circuit is probably best known from Jim Williams’ series of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61,
user group sci.electroncs.design Wed, Oct 1 2003 5:35 pm) and always produces a slightly non-sinusoidal output."
As Jim Williams points out, this circuit can offer good efficiency – 90% - when driving difficult loads. It is a rather cranky circuit, which works best if of the resonant tank has a Q of between 5 and 10 – according to Tony Williams (on the
photomultiplier power supply generating 1kV or more from a 12V supply.
It's particular virtue is that it copes with high parallel capacitance you get in the kind of high-turns ratio step-up transformers that you need when generating high voltages. Peter Baxandall seems to have invented it when he needed a compact
5 decades, and may no longer be relevant.
From what I can see that CCFL stuff has been beaten to death by the lightbulb industry. They don't even use a transformer, they use a resonant LC driven by an off-the-line half bridge switch. The JW, and certainly Baxandall, predates all that by 4-
large screen displays.Cold cathode lamps don't seem to be used any more. Lap-tops rely on arrays of multiplexed light-emitting diodes for their displays - I think organic LEDS dominate that market now, but it's been a while since I paid much attention to the mechanics of
The LC resonant serves a dual mode of resonating to strike the initial arc and then relaxing to form a simple ballast for the load.
Cold cathode lamps rely on a glow discharge, not an arc, as you'd be a aware if you knew anything about the subject. The very name "cold cathode lamp" would have told you about that if you had the barest minimum of background knowledge.
Not interested in that kind of detail...could care less.
Marry Sloman. You are perfect for one another.
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