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Re: LM324 based automatic voltage stabilizer circuit simulation
Bumping this to the top I had uploaded a couple of circuits yesterday. Can an LTspice subcircuit guru help me with passing a parameter, as below?
relay_driver: can use this subcircuit for each of the three voltage sense and relay switching circuits of the diagram.
Relay_Driver.asc needs a little more tweaking, but it was late and I ran out of stem. I was having trouble passing the internal pot’s wiper position parameter. As it is, it works stand-alone in the _test.asc, but there is currently no means to make three copies with different Wp values. The potmet device uses Fz as its wiper value. I need to get Wp1, 2, 3, etc. in the top level circuit pushed through to the subcircuit, as Fz internally…
Thanks, Dave |
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Re: LM324 based automatic voltage stabilizer circuit simulation
“Correcting” V1 to 311V peak / 220 V RMS, after a full minute of settling down, I measure: rb: RMS(v(b))=210.556 FROM 0 TO 0.02 rc: RMS(v(c))=219.988 FROM 0 TO 0.02 rd: RMS(v(d))=229.341 FROM 0 TO 0.02 re: RMS(v(e))=238.728 FROM 0 TO 0.02 rf: RMS(v(f))=18.0041 FROM 0 TO 0.02
These are almost identical to the peak measurements at 1005ms, with V1 at 220.: vb: v(b)=210.591 at 0.005 vc: v(c)=220 at 0.005 vd: v(d)=229.38 at 0.005 ve: v(e)=238.768 at 0.005 vf: v(f)=18.007 at 0.005
They seem pretty close. As for overlapping text, I’m running version XVII, and I know there were font differences in 24.
Dave
From: LTspice@groups.io <LTspice@groups.io> On Behalf Of
Andy I via groups.io
Sent: Saturday, December 28, 2024 9:39 PM To: LTspice@groups.io Subject: EXTERNAL: Re: [LTspice] LM324 based automatic voltage stabilizer circuit simulation
On Sat, Dec 28, 2024 at 02:50 PM, Bell, Dave wrote:
It's still got the wrong voltage source. V1 is a 155 V RMS source. It does not represent a 220 V mains voltage.
Text is overlapping. Messy.
Measurements should look at RMS voltages, not instantaneous values at a somewhat arbitrary phase.
Andy
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Re: Autotransformer deep questions!
That's usually the value that matters. At
lower voltages, the (calculated) inductance is normally higher,
because of the nonlinearity of the B-H curve. But the
small-signal inductance (as measured by an 'inductance meter' is
likely to be lower, for the same reason. The core permeability
is lower at very low currents. On 2024-12-29 22:02, Tony Casey wrote:
-- OOO - Own Opinions Only Best Wishes John Woodgate Keep trying |
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Re: Autotransformer deep questions!
On 29/12/2024 21:24, Suusi M-B via
groups.io wrote:
If you're talking about autotransformers with Si-iron laminate cores, then be careful with inductance measurements. John Woodgate kindly reminded me previously about relying on small-signal measurements on mains transformers. Remanence is the issue - in essence, what you measure depends on the point in the current waveform at which the circuit was last broken. It will be different each time you measure it. The only reliable method is to measure the magnetising current at the rated (primary) voltage. -- Regards,
Tony |
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Re: Autotransformer deep questions!
:{) As long as the one working with the model understands that it’s not really 220VRMS, it works. In the end, it’s one constant to change, and it all works the same.
I doubt even 1 Amp is used at 18V; that load was arbitrary. Mainly, I was trying to get the turns/inductance ratios correct. Those I parameterized are close, probably close enough. (I still don’t understand all the interactions between windings, or why the inductance ratio between the nominal 220V tap and the 18V winding are close to the “correct” numbers, but not close enough.)
Dave
From: LTspice@groups.io <LTspice@groups.io>
On Behalf Of Suusi M-B via groups.io
Sent: Sunday, December 29, 2024 12:25 PM To: LTspice@groups.io Subject: EXTERNAL: Re: [LTspice] Autotransformer deep questions!
Just a couple or three observations: 3. I am never happy with not multiplying the RMS voltage by 1.4142 to get the peak voltage. I get why you did it that way but… Shudder.
Have fun
Suusi M-B
From:
LTspice@groups.io On Behalf Of MD MUBDIUL HASAN via groups.io
I’ll update it tomorrow; getting late here. I got answers to most of my issues, so it may be a useful stating point.
>>>> Thank you very much, the schematics I showed must have some problem but its sure that autotransformer plays a vital role here. I have another design which is transformer less, lets see.
From:
LTspice@groups.io <LTspice@groups.io>
On Behalf Of MD MUBDIUL HASAN via groups.io
Dave Great job 👏 I will look at it.
On Thursday, December 26, 2024 at 09:41:03 PM GMT+1, Bell, Dave via groups.io <dave.bell@...> wrote:
Please see my recent upload, Autotransformer.zip
I need some tutorials regarding autotransformer modelling! I was intrigued by Hassan's AC Stabilizer and tried to model TR1 The model differed from my expectations in several ways. 1: Why do the tap-to-tap voltages differ, with equal inductances? 2: Why is the separate 18V winding so different? 2a: Why is it more different when I separate the Kxxx directives? 3: Why do the outputs throw infinities with small or megohm loads, but not when 1G or open??
Dave
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Re: Autotransformer deep questions!
Just a couple or three observations: 3. I am never happy with not multiplying the RMS voltage by 1.4142 to get the peak voltage. I get why you did it that way but… Shudder.
Have fun
Suusi M-B
From: LTspice@groups.io On Behalf Of MD MUBDIUL HASAN via groups.io
Sent: 28 December 2024 16:06 To: ltspice@groups.io Subject: Re: [LTspice] Autotransformer deep questions!
I’ll update it tomorrow; getting late here. I got answers to most of my issues, so it may be a useful stating point.
>>>> Thank you very much, the schematics I showed must have some problem but its sure that autotransformer plays a vital role here. I have another design which is transformer less, lets see.
From: LTspice@groups.io <LTspice@groups.io> On Behalf Of MD MUBDIUL HASAN via groups.io
Dave Great job 👏 I will look at it.
On Thursday, December 26, 2024 at 09:41:03 PM GMT+1, Bell, Dave via groups.io <dave.bell@...> wrote:
Please see my recent upload, Autotransformer.zip
I need some tutorials regarding autotransformer modelling! I was intrigued by Hassan's AC Stabilizer and tried to model TR1 The model differed from my expectations in several ways. 1: Why do the tap-to-tap voltages differ, with equal inductances? 2: Why is the separate 18V winding so different? 2a: Why is it more different when I separate the Kxxx directives? 3: Why do the outputs throw infinities with small or megohm loads, but not when 1G or open??
Dave |
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Re: Autotransformer deep questions!
I’ll look at that, thanks!
Switching primary taps will throw off the 18VAC winding, which adds complexity to analyzing the AC Stabilizer over-all design, but that’s the way Hasan’s (photo) design has it. There’s another separate low voltage transformer that may be the same 18V, but driven from the nominal 220V (RMS, Andy!) input.
One of those low voltage windings is used as the signal source for the three threshold detected relay drivers that move the tap point, so, yeah, it’s a little obscure to analyze. One hopes it would settle into one mode without dithering when the input is near a switch point!
Dave
From: LTspice@groups.io <LTspice@groups.io> On Behalf Of
eetech00 via groups.io
Sent: Sunday, December 29, 2024 11:48 AM To: LTspice@groups.io Subject: EXTERNAL: Re: [LTspice] Autotransformer deep questions!
Hi
Your uploaded example appears to be a transformer with a multi-tapped primary that maintains 18v output at the secondary.
I've uploaded an example "Multi_Tapped_Transformer_eT.zip"
eT |
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Re: LM324 based automatic voltage stabilizer circuit simulation
A wee bit, perhaps, but it’s a work in progress, and maybe a collaborative effort.
RE: The measurements, I tried 0 compression, and the voltages changed by mV’s. There were markable fewer data points before that, but I’m measuring where the derivative is practically zero, so…
From: LTspice@groups.io <LTspice@groups.io> On Behalf Of
Andy I via groups.io
Sent: Sunday, December 29, 2024 6:15 AM To: LTspice@groups.io Subject: EXTERNAL: Re: [LTspice] LM324 based automatic voltage stabilizer circuit simulation
On Sun, Dec 29, 2024 at 01:07 AM, Bell, Dave wrote:
I suppose not. But your .MEAS commands are wrong. If you are fortunate and the phase shifts are small enough, it might be "close enough for government work" (as they say) and you might get lucky and happen to see numbers that agree with your expectations. But it is just plain wrong.
And it's a wee bit dangerous to simulate the wrong thing too and then pass it around for thousands of others to see.
Andy
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Re: LM324 based automatic voltage stabilizer circuit simulation
I’m well aware of that, Andy! I set it at 220 so I could easily read the plot or in .meas, as if it were RMS. Ratiometrically, it really doesn’t matter, does it?
Dave
From: LTspice@groups.io <LTspice@groups.io> On Behalf Of
Andy I via groups.io
Sent: Saturday, December 28, 2024 9:39 PM To: LTspice@groups.io Subject: EXTERNAL: Re: [LTspice] LM324 based automatic voltage stabilizer circuit simulation
On Sat, Dec 28, 2024 at 02:50 PM, Bell, Dave wrote:
It's still got the wrong voltage source. V1 is a 155 V RMS source. It does not represent a 220 V mains voltage.
Text is overlapping. Messy.
Measurements should look at RMS voltages, not instantaneous values at a somewhat arbitrary phase.
Andy
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Re: LM324 based automatic voltage stabilizer circuit simulation
I uploaded a couple of circuits, parts that may be useful in the AC Stabilizer design: TR1: a mostly successful basic simulation of the main autotransformer relay_driver: can use this subcircuit for each of the three voltage sense and relay switching circuits of the diagram.
Relay_Driver.asc needs a little more tweaking, but it was late and I ran out of stem. I was having trouble passing the internal pot’s wiper position parameter. As it is, it works stand-alone in the _test.asc, but there is currently no means to make three copies with different Wp values. The potmet circuit uses Fz as it’s wiper value. I need to get Wpxx in the top level circuit pushed through to the subcircuit, as Fz internally…
Dave |
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Re: LM324 based automatic voltage stabilizer circuit simulation
Kerim, can you share that front end ACV range extender circuit? It sounds intriguing!
Dave
From: LTspice@groups.io <LTspice@groups.io> On Behalf Of
Kerim via groups.io
Sent: Wednesday, December 25, 2024 3:32 PM To: LTspice@groups.io Subject: EXTERNAL: Re: [LTspice] LM324 based automatic voltage stabilizer circuit simulation
Off topic
As most engineers are doing, I took advantage of the SMPS availability (say 24V, 1A) whose input can vary from 100 to 240V, to supply my boards. But I had to also design a small circuit to increase this range. By connecting it between the mains voltage and the SMPS input, the range becomes from 70 to 400 Vac.
Thanks to LTspice, I was able to test every design before drawing its final PCBs. I substitute the MCU by logic elements. _._,_._,_ |
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Re: Autotransformer deep questions!
I did an autotransformer example/derivation a while back HERE It's for an RF application but should be general enough to use elsewhere. |
Bell, Dave
John Woodgate
Tony Casey
Jim, K7JEB
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