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Re: PULSE default rise and fall times (Trise=0 Tfall=0) (was: ISL70444SEH declaration issue?)
开云体育Thanks, Tony.? Per-Ton =
Toff+Trise+Tfall. ======================================================================================
Best wishes John Woodgate OOO-Own Opinions Only Rayleigh, Essex UK I hear, and I forget. I see, and I remember. I do, and I understand. Xunzi (340 - 245 BC) On 2023-07-15 14:04, Tony Casey wrote:
Trise = Tfall = min(Ton/10, (Per-Ton)/10) |
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Re: PULSE default rise and fall times (Trise=0 Tfall=0) (was: ISL70444SEH declaration issue?)
开云体育Trise = Tfall = min(Ton/10, (Per-Ton)/10).. would be a more succinct way to express it. Thanks for dragging it out of me. ? --
Regards, Tony On 15/07/2023 14:57, John Woodgate
wrote:
Good, but what does 'the law is mirrored' mean? |
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Re: PULSE default rise and fall times (Trise=0 Tfall=0) (was: ISL70444SEH declaration issue?)
开云体育Good, but what does 'the law is
mirrored' mean? ======================================================================================
Best wishes John Woodgate OOO-Own Opinions Only Rayleigh, Essex UK I hear, and I forget. I see, and I remember. I do, and I understand. Xunzi (340 - 245 BC) On 2023-07-15 13:52, Tony Casey wrote:
I have uploaded a test schematic that measures the actual rise and fall times of a pulse source with default rise and fall times, i.e. both set to zero. |
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Re: PULSE default rise and fall times (Trise=0 Tfall=0) (was: ISL70444SEH declaration issue?)
开云体育I have uploaded a test schematic that measures the actual rise and fall times of a pulse source with default rise and fall times, i.e. both set to zero.The measurements show that the algorithm is: For Ton ≤ Per/2: Trise = Tfall = Ton/10 For Ton > Per/2: the law is mirrored I have verified this for Ton = Per/1000 to 999*Per/1000. As a consequence of: Toff = Per - Ton - Trise - Tfall .. the measured duty cycle (at the 50% points) is a non-linear function or Ton/Per, being 0.55 at Ton/Per=0.5. This is the reason why to set a 50% actual duty cycle: Ton = (Per - Trise - Tfall)/2 --
Regards, Tony On 14/07/2023 23:32, Bell, Dave wrote:
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Re: Spark gap physics.
开云体育Hello All Bonkers wrote:
Forgive me, I took a bit of dramatic license. That plant was completed in 1954 and I would assume that there were FMEA analyses performed on commercial switch gear of that era. I agree that it probably was (should have been) a redundant air blast system. But wow, what a spectacular failure. All for now
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Re: PULSE default rise and fall times (Trise=0 Tfall=0) (was: ISL70444SEH declaration issue?)
开云体育I dug out the test case, and tried down into femtoseconds. Best I could get was 100fs for a setting of 100fs ? Dave ? From: [email protected] <[email protected]> On Behalf Of
Bell, Dave (US)
Sent: Friday, July 14, 2023 1:06 PM To: [email protected] Subject: EXTERNAL: Re: [LTspice] ISL70444SEH declaration issue? ? Andy wrote: “Remember to never set Trise or Tfall to 0.? That signals SPICE (and LTspice) to substitute non-zero default values, and they won't be anywhere near 0.? It's a SPICE thing.” ? Indeed! I tried this a while back. 1ns yielded 1ns Tr and Tf 0 yielded 100us Tr and Tf 1p was too fast to zoom into, but jumping to marked data points, I got … 1ps ? ? Dave ? |
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PULSE default rise and fall times (Trise=0 Tfall=0) (was: ISL70444SEH declaration issue?)
开云体育Andy wrote: “Remember to never set Trise or Tfall to 0.? That signals SPICE (and LTspice) to substitute non-zero default values, and they won't be anywhere near 0.? It's a SPICE thing.” ? Indeed! I tried this a while back. 1ns yielded 1ns Tr and Tf 0 yielded 100us Tr and Tf 1p was too fast to zoom into, but jumping to marked data points, I got … 1ps ? ? Dave ? |
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Re: LTC1922/LTC3722 model and simulation
开云体育For some reason, the examples\jigs folder has been redesignated as examples\Applications in LTspice 17.1.x.On 14/07/2023 17:02, Udo
Huhn-Rohrbacher via groups.io wrote:
LTspice offers example circuits under > examples \jigs\1922-1 ,as well as for the 3722-1. --
Regards, Tony |
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Re: LTC1922/LTC3722 model and simulation
开云体育It would be much better for you
to upload your .ASC and all other files required to run it
(but not .RAW and .LOG) as a ZIP archive to Files => Temp
and then tell us you did that. ======================================================================================
Best wishes John Woodgate OOO-Own Opinions Only Rayleigh, Essex UK I hear, and I forget. I see, and I remember. I do, and I understand. Xunzi (340 - 245 BC) On 2023-07-14 15:55, R Clark via
groups.io wrote:
Hello , I am trying to simulate from LTspice libray LTC1922-1 and LTC3722 |
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Re: Spark gap physics.
开云体育We do not like being sent to
third-party sites in order to try to solve problems. But there
is no objection to posting (no more than a few) links purely
for information. ======================================================================================
Best wishes John Woodgate OOO-Own Opinions Only Rayleigh, Essex UK I hear, and I forget. I see, and I remember. I do, and I understand. Xunzi (340 - 245 BC) On 2023-07-14 14:43, Andrew Lohmann
wrote:
You do not need to look at my blog page I know that this group does not like outside links being posted but here it is anyway;? |
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Re: Regarding basic simulation of ACST
开云体育There are a whole lot of issues with the model library and the ACST symbol. The various subcircuits in the library have conflicting pin orders.You have called the called the model ACST310-8FP, which has a pin order of AKG, but the symbol you used has a pin order of AGK, which I guess was obtained from Autogenerating one from the ACST subcircuit. The error messages: Questionable use of curly braces in ".model dak d (is=5e-16 rs={rd})" ??? Error: undefined symbol in: "[rd]" Questionable use of curly braces in ".model doff1_t d (bv={bvn})" ??? Error: undefined symbol in: "[bvn]" Questionable use of curly braces in ".model doff2_t d (bv={bvp})" ??? Error: undefined symbol in: "[bvp]" Circuit: * D:\Simulations\LTspice\_Temp\karamchandani.jagdish\ACST_Files\ACST.asc Error on line 52 : .model doff2_t d (bv=(bvp)) ?? ?* Unrecognized parameter "bvp" -- ignored Error on line 51 : .model doff1_t d (bv=(bvn)) ?? ?* Unrecognized parameter "bvn" -- ignored Error on line 50 : .model dak d (is=5e-16 rs=(rd)) ?? ?* Unrecognized parameter "rd" -- ignored ..arise because the diode models are defined at the top level of the model file where the parameters in curly braces are not visible. Moving the diode models inside the top level subcircuit (ACST) fixes that and the circuit then runs. cut and paste those lines just above the ".ends" line of the "ACST" subcircuit. Did you notice the advisory in the model file?: *?? For a correct ACST behavior, the "Maximum step size" must be below *?? or equal 20?s. The way your schematic is configured,
the triac never actually turns on - you just get mVs across R1 -
"off" leakage. Perhaps that was your intention.
As it stands, I'm not sure it working with the correct model parameters because of the issues mentions at the top. But it does run. Maybe I'll fix the model file properly, but it will take time to verify it. The other thing I noticed was that your resistor values have "E" appended. This is ignored unless a number follows the "E", in which case it becomes an exponent of 10. "E" on it's own is not a valid range multiplier. Exceptionally, "R" can be used instead of a decimal point in resistor values, but the only accepted range multipliers are: f, p, n, u, m, k, Meg, G, and T. They are not case-sensitive, lower and upper case are just used as convention and to preserve sensibilities. --
Regards, Tony On 14/07/2023 08:11, Jagdish Karamchandani via groups.io wrote: I am trying to make overvoltage switch using ACST from STmicroelectronics but seems can't simulate its spice model. Any help will be appreciated. Please find all the files over here, |
John Woodgate
Tony Casey
eewiz
Bell, Dave