Re: Generation of a discrete number of pulses using a triggering signal
--- In LTspice@..., Ganesan <dg1@...> wrote:
Helmut,
I had to make the time step less than 10u in the transient
analysis to keep the triggered pulses from looking weird.
Another interpolation artifact?
Cheers
AG
Hello AG, Thanks for the hint with the maximum time step. I have uploaded an updated version. Files > Tut > TRIGGER > trigger_pulse_burst.asc Best regards, Helmut
|
Re: Generation of a discrete number of pulses using a triggering signal
Helmut,
I had to make the time step less than 10u in the transient analysis to
keep the triggered pulses from looking weird.. Another interpolation
artifact?
Cheers
AG
toggle quoted message
Show quoted text
On 9/25/2011 4:01 PM, Helmut wrote:
--- In LTspice@... <mailto:LTspice%40yahoogroups.com>,
"kostas045" <kostas045@...> wrote:
Hi all,
I have been trying to generate a discrete number of pulses based on
a triggering signal, to drive a mosfet. The trick is that a want the
sequence of pulses to be repetitive during the simulation, i.e. I dont
want to generate it only once!
For example given a triggering event, like a sinus reaching its peak
value or zero or whatever, a first sequence of X high frequency pulses
will be generated. The second sequence will be generated at the next
triggering event and so on...
I have been trying with a BV source and the keyword ''Trigger'' (as
I found in some other posts in this forum) but until now all my
efforts have been proven unworthy! Any help will be appreciated!
Thanks!
P.S. Great forum guys! Gongrats!
Hello,
The TRIGGER command only works with V-sources.
I have made an example for you using the a pulse source
with the parameter NCYCLES set to the number of pulses.
Files > Tut > TRIGGER > trigger_pulse_burst.asc
Best regards,
Helmut
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Re: Generation of a discrete number of pulses using a triggering signal
--- In LTspice@..., "Helmut" <helmutsennewald@...> wrote:
--- In LTspice@..., "kostas045" <kostas045@> wrote:
Hi all,
I have been trying to generate a discrete number of pulses based on a triggering signal, to drive a mosfet. The trick is that a want the sequence of pulses to be repetitive during the simulation, i.e. I dont want to generate it only once!
For example given a triggering event, like a sinus reaching its peak value or zero or whatever, a first sequence of X high frequency pulses will be generated. The second sequence will be generated at the next triggering event and so on...
I have been trying with a BV source and the keyword ''Trigger'' (as I found in some other posts in this forum) but until now all my efforts have been proven unworthy! Any help will be appreciated!
Thanks!
P.S. Great forum guys! Gongrats!
Hello,
The TRIGGER command only works with V-sources.
I have made an example for you using the a pulse source
with the parameter NCYCLES set to the number of pulses.
Files > Tut > TRIGGER > trigger_pulse_burst.asc
Best regards,
Helmut
Super! Exactly what I was aiming for! Thank you very much Helmut! Regards! Kostas
|
Re: Generation of a discrete number of pulses using a triggering signal
--- In LTspice@..., "kostas045" <kostas045@...> wrote:
Hi all,
I have been trying to generate a discrete number of pulses based on a triggering signal, to drive a mosfet. The trick is that a want the sequence of pulses to be repetitive during the simulation, i.e. I dont want to generate it only once!
For example given a triggering event, like a sinus reaching its peak value or zero or whatever, a first sequence of X high frequency pulses will be generated. The second sequence will be generated at the next triggering event and so on...
I have been trying with a BV source and the keyword ''Trigger'' (as I found in some other posts in this forum) but until now all my efforts have been proven unworthy! Any help will be appreciated!
Thanks!
P.S. Great forum guys! Gongrats!
Hello, The TRIGGER command only works with V-sources. I have made an example for you using the a pulse source with the parameter NCYCLES set to the number of pulses. Files > Tut > TRIGGER > trigger_pulse_burst.asc Best regards, Helmut
|
Generation of a discrete number of pulses using a triggering signal
Hi all,
I have been trying to generate a discrete number of pulses based on a triggering signal, to drive a mosfet. The trick is that a want the sequence of pulses to be repetitive during the simulation, i.e. I dont want to generate it only once!
For example given a triggering event, like a sinus reaching its peak value or zero or whatever, a first sequence of X high frequency pulses will be generated. The second sequence will be generated at the next triggering event and so on...
I have been trying with a BV source and the keyword ''Trigger'' (as I found in some other posts in this forum) but until now all my efforts have been proven unworthy! Any help will be appreciated!
Thanks!
P.S. Great forum guys! Gongrats!
|
Re: netlisting a potentiometer
that worked, easy enough.? thanks helmut!
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Show quoted text
----- Original Message ----- From: "Helmut" <helmutsennewald@...> To: LTspice@... Sent: Sunday, September 25, 2011 10:55:21 AM Subject: [LTspice] Re: netlisting a potentiometer ? --- In LTspice@... , dylanfree@... wrote: Case: exporting??the netlist in PADS format??from LTSPICE
and import?into my PCB layout program called FreePCB.
Issue: I model my potentiometer as a?R?circuit element for
simulation?in LTSPICE, but it will netlist as a two-terminal
reference designator, which I can not attach a terminal
?potentiometer footprint in FreePCB.? Making a subcircuit out
of two R circuit elements results in, as you might expect,
?qty=2 reference designators requiring an individual two-
terminal footprint for each.? I suppose I could put in a
three terminal circuit element (like M for example) and
export-->netlist that, but my schematic would not match the
PCB?and the sims would not represent the design.
The only three terminal circuit elements I see from the
LTSPICE Help are J(jfet),M(mosfet),Q(bjt), S(voltage
controlled switch),U(uniform transmission line),W(current-
controlled swtich)? <-- Is there some way to use one of
these?to netlist a three-terminal pot and still have
functional LTSPICE simulations? Hello, There is a potentiometer symbol in our Files section. Files > Lib > Potentiometer > poetentiometer.asy Files > Lib > Potentiometer > poetentiometer.sub Test circuit: Files > Lib > Potentiometer > poetentiometer_test.asac I recommend to rename the reference designator of the potentiometer from e.g. U1 to P1 in the schematic. Best regards, Helmut [Non-text portions of this message have been removed]
|
Re: netlisting a potentiometer
--- In LTspice@..., dylanfree@... wrote: Case: exporting??the netlist in PADS format??from LTSPICE
and import?into my PCB layout program called FreePCB.
Issue: I model my potentiometer as a?R?circuit element for
simulation?in LTSPICE, but it will netlist as a two-terminal
reference designator, which I can not attach a terminal
?potentiometer footprint in FreePCB.? Making a subcircuit out
of two R circuit elements results in, as you might expect,
?qty=2 reference designators requiring an individual two-
terminal footprint for each.? I suppose I could put in a
three terminal circuit element (like M for example) and
export-->netlist that, but my schematic would not match the
PCB?and the sims would not represent the design.
The only three terminal circuit elements I see from the
LTSPICE Help are J(jfet),M(mosfet),Q(bjt), S(voltage
controlled switch),U(uniform transmission line),W(current-
controlled swtich)? <-- Is there some way to use one of
these?to netlist a three-terminal pot and still have
functional LTSPICE simulations? Hello, There is a potentiometer symbol in our Files section. Files > Lib > Potentiometer > poetentiometer.asy Files > Lib > Potentiometer > poetentiometer.sub Test circuit: Files > Lib > Potentiometer > poetentiometer_test.asac I recommend to rename the reference designator of the potentiometer from e.g. U1 to P1 in the schematic. Best regards, Helmut
|
netlisting a potentiometer
Case: exporting?the netlist in PADS format?from LTSPICE and import?into my PCB layout program called FreePCB.
Issue: I model my potentiometer as a?R?circuit element for simulation?in LTSPICE, but it will netlist as a two-terminal reference designator, which I can not attach a three-terminal?potentiometer footprint in FreePCB.? Making a subcircuit out of two R circuit elements results in, as you might expect,?qty=2 reference designators requiring an individual two-terminal footprint for each.? I suppose I could put in a three terminal circuit element (like M for example) and export-->netlist that, but my schematic would not match the PCBA?and the sims would not represent the design.
The only three terminal circuit elements I see from the LTSPICE Help are J(jfet),M(mosfet),Q(bjt), S(voltage controlled switch),U(uniform transmission line),W(current-controlled swtich)? <-- Is there some way to use one of these?to netlist a three-terminal pot and still have functional LTSPICE simulations?
[Non-text portions of this message have been removed]
|
Re: Inductor initial conditions
Thank you.
I am sure that there is a very good reason.
I am grateful to him that he has made this great program available.
Helmut wrote:
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--- In LTspice@... <mailto:LTspice%40yahoogroups.com>,
"E.A.Neonakis" <eaneonakis@...> wrote:
Dear Mr Sennewald
May I ask what was intended in this case? Are there
circumstances that this differentiated behaviour between
initial capacitor voltages and inductor currents is useful?
Best Regards,
E.A.Neonakis
Hello
--- Mike
In LTspice, an .ic statement for a node voltage, e.g.,
.IC V(out1)=10 works(whether UIC is specified or not).
However, .ic I(L1) will never work in LTspice because I(L1)
is not a voltage. The only place LTspice accepts and IC for
a component is on the component.
...
--- end
I don't know why Mike has chosen this definition, but I guess
he had a good reason to implement it this way.
Best regards,
Helmut
Helmut wrote:
.ic I(L1)=1 --> used
I have discussed this case with Mike in the last few hours.
Mike told me that the behavior of LTspice is as intended,
|
--- In LTspice@..., Kesara De Costa <kmde_costa@...> wrote:
Unsubscribe
Hello, I have set your "Email Delivery" to "No email". This is my recommended setting. Now you don't get the messages in your email box, but you can still read the messages with the web browser. Normally you should manage your group's membership by yourself. Best regards, Helmut
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Re: Inductor initial conditions
I understand .. On the jovial side, are you and Bill Clinton friends..?
cheers
AG
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Show quoted text
On 9/25/2011 6:00 AM, Helmut wrote:
--- In LTspice@... <mailto:LTspice%40yahoogroups.com>,
Ganesan <dg1@...> wrote:
Helmut,
Am I missing something?
LTspice says
"
.TRAN Modifiers
UIC: Skip the D.C. operating solution and use user-specified
initial conditions.
This specifications doesn't tell which initial conditions.
It's only valid for node voltages in LTspice as I cited in my
previous email. That's how it works today.
Best regards,
Helmut___
|
Re: Inductor initial conditions
--- In LTspice@..., Ganesan <dg1@...> wrote:
Helmut,
Am I missing something?
LTspice says
"
.TRAN Modifiers
UIC: Skip the D.C. operating solution and use user-specified
initial conditions.
This specifications doesn't tell which initial conditions. It's only valid for node voltages in LTspice as I cited in my previous email. That's how it works today. Best regards, Helmut
steady: Stop the simulation when steady state has been reached.
nodiscard: Don't delete the part of the transient simulation before
steady state is reached.
startup: Solve the initial operating point with independent voltage and
current sources turned off. Then start the transient analysis and turn
these sources on in the first 20 us of the simulation.
step: Compute the step response of the circuit.
"
Cheers
AG
On 9/25/2011 5:06 AM, Helmut wrote:
--- In LTspice@... <mailto:LTspice%40yahoogroups.com>,
Ganesan <dg1@> wrote:
The help section of .IC in LTspice says:
"
.IC -- Set Initial Conditions
The .ic directive allows initial conditions for transient
analysis to be specified. Node voltages and inductor
currents may be specified. A DC solution is performed using
the initial conditions as constraints. Note that although
inductors are normally treated as short circuits in the DC
solution in other SPICE programs, if an initial current is
specified, they are treated as infinite-impedance current
sources in LTspice.
Syntax: .ic [V(<n1>)=<voltage>] [I(<inductor>)=<current>]
Example: .ic V(in)=2 V(out)=5 V(vc)=1.8 I(L1)=300m
"
It should probably be replaced by:
"
In LTspice, an .ic statement for a node voltage, e.g.,
.IC V(out1)=10 works(whether UIC is specified or not).
However, .ic I(L1) will never work in LTspice because I(L1)
is not a voltage. The only place LTspice accepts an IC for
a component is on the component.
"
Helmut, shouldn't this be corrected given what you found ..?
Cheers
AG
Hello AG,
This help section doesn't mention the option "uic" of .TRAN.
When you don't use "uic", LTspice uses .ic I(L1) as mentioned
in this help section.
Best regards,
Helmut
Hello
--- Mike
In LTspice, an .ic statement for a node voltage, e.g.,
.IC V(out1)=10 works(whether UIC is specified or not).
However, .ic I(L1) will never work in LTspice because I(L1)
is not a voltage. The only place LTspice accepts and IC for
a component is on the component.
...
--- end
I don't know why Mike has chosen this definition, but I guess
he had a good reason to implement it this way.
Best regards,
Helmut
Switch to: Text-Only
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[Non-text portions of this message have been removed]
|
Re: Inductor initial conditions
Helmut,
Am I missing something?
LTspice says
"
.TRAN Modifiers
UIC: Skip the D.C. operating solution and use user-specified initial
conditions.
steady: Stop the simulation when steady state has been reached.
nodiscard: Don't delete the part of the transient simulation before
steady state is reached.
startup: Solve the initial operating point with independent voltage and
current sources turned off. Then start the transient analysis and turn
these sources on in the first 20 us of the simulation.
step: Compute the step response of the circuit.
"
Cheers
AG
toggle quoted message
Show quoted text
On 9/25/2011 5:06 AM, Helmut wrote:
--- In LTspice@... <mailto:LTspice%40yahoogroups.com>,
Ganesan <dg1@...> wrote:
The help section of .IC in LTspice says:
"
.IC -- Set Initial Conditions
The .ic directive allows initial conditions for transient
analysis to be specified. Node voltages and inductor
currents may be specified. A DC solution is performed using
the initial conditions as constraints. Note that although
inductors are normally treated as short circuits in the DC
solution in other SPICE programs, if an initial current is
specified, they are treated as infinite-impedance current
sources in LTspice.
Syntax: .ic [V(<n1>)=<voltage>] [I(<inductor>)=<current>]
Example: .ic V(in)=2 V(out)=5 V(vc)=1.8 I(L1)=300m
"
It should probably be replaced by:
"
In LTspice, an .ic statement for a node voltage, e.g.,
.IC V(out1)=10 works(whether UIC is specified or not).
However, .ic I(L1) will never work in LTspice because I(L1)
is not a voltage. The only place LTspice accepts an IC for
a component is on the component.
"
Helmut, shouldn't this be corrected given what you found ..?
Cheers
AG
Hello AG,
This help section doesn't mention the option "uic" of .TRAN.
When you don't use "uic", LTspice uses .ic I(L1) as mentioned
in this help section.
Best regards,
Helmut
Hello
--- Mike
In LTspice, an .ic statement for a node voltage, e.g.,
.IC V(out1)=10 works(whether UIC is specified or not).
However, .ic I(L1) will never work in LTspice because I(L1)
is not a voltage. The only place LTspice accepts and IC for
a component is on the component.
...
--- end
I don't know why Mike has chosen this definition, but I guess
he had a good reason to implement it this way.
Best regards,
Helmut
Switch to: Text-Only
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<mailto:LTspice-digest@...?subject=Email%20Delivery:%20Digest>
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Re: Inductor initial conditions
I've uploaded
Files --> temp
Zero_Minus _And_Zero_Plus.asc
<>
These are from my notes from a number of years ago..
(At zero plus an additional switch is needed across the current sources
to keep them from going to infinite voltages..)
At zero minus most programs use the incidence matrix and the nodal
admittance matrix, to resolve branch currents and nodal voltages into
component currents and component voltages.. LTspice apparently does
this only partially..
cheers
AG
Any feedback will be appreciated....
==========================================================================================
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Show quoted text
On 9/25/2011 4:37 AM, Ganesan wrote:
The help section of .IC in LTspice says:
"
.IC -- Set Initial Conditions
The .ic directive allows initial conditions for transient analysis to be
specified. Node voltages and inductor currents may be specified. A DC
solution is performed using the initial conditions as constraints. Note
that although inductors are normally treated as short circuits in the DC
solution in other SPICE programs, if an initial current is specified,
they are treated as infinite-impedance current sources in LTspice.
Syntax: .ic [V(<n1>)=<voltage>] [I(<inductor>)=<current>]
Example: .ic V(in)=2 V(out)=5 V(vc)=1.8 I(L1)=300m
"
It should probably be replaced by:
"
In LTspice, an .ic statement for a node voltage, e.g.,
.IC V(out1)=10 works(whether UIC is specified or not).
However, .ic I(L1) will never work in LTspice because I(L1)
is not a voltage. The only place LTspice accepts an IC for
a component is on the component.
"
Helmut, shouldn't this be corrected given what you found ..?
Cheers
AG
Hello
--- Mike
In LTspice, an .ic statement for a node voltage, e.g.,
.IC V(out1)=10 works(whether UIC is specified or not).
However, .ic I(L1) will never work in LTspice because I(L1)
is not a voltage. The only place LTspice accepts and IC for
a component is on the component.
...
--- end
I don't know why Mike has chosen this definition, but I guess
he had a good reason to implement it this way.
Best regards,
Helmut
Switch to: Text-Only
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Daily Digest
<mailto:LTspice-digest@...?subject=Email%20Delivery:%20Digest>
. Unsubscribe
<mailto:LTspice-unsubscribe@...?subject=Unsubscribe> .
Terms of Use <>
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Re: Inductor initial conditions
--- In LTspice@..., Ganesan <dg1@...> wrote:
The help section of .IC in LTspice says:
"
.IC -- Set Initial Conditions
The .ic directive allows initial conditions for transient
analysis to be specified. Node voltages and inductor
currents may be specified. A DC solution is performed using
the initial conditions as constraints. Note that although
inductors are normally treated as short circuits in the DC
solution in other SPICE programs, if an initial current is
specified, they are treated as infinite-impedance current
sources in LTspice.
Syntax: .ic [V(<n1>)=<voltage>] [I(<inductor>)=<current>]
Example: .ic V(in)=2 V(out)=5 V(vc)=1.8 I(L1)=300m
"
It should probably be replaced by:
"
In LTspice, an .ic statement for a node voltage, e.g.,
.IC V(out1)=10 works(whether UIC is specified or not).
However, .ic I(L1) will never work in LTspice because I(L1)
is not a voltage. The only place LTspice accepts an IC for
a component is on the component.
"
Helmut, shouldn't this be corrected given what you found ..?
Cheers
AG
Hello AG, This help section doesn't mention the option "uic" of .TRAN. When you don't use "uic", LTspice uses .ic I(L1) as mentioned in this help section. Best regards, Helmut Hello
--- Mike
In LTspice, an .ic statement for a node voltage, e.g.,
.IC V(out1)=10 works(whether UIC is specified or not).
However, .ic I(L1) will never work in LTspice because I(L1)
is not a voltage. The only place LTspice accepts and IC for
a component is on the component.
...
--- end
I don't know why Mike has chosen this definition, but I guess
he had a good reason to implement it this way.
Best regards,
Helmut
|
Re: Inductor initial conditions
The help section of .IC in LTspice says:
"
.IC -- Set Initial Conditions
The .ic directive allows initial conditions for transient analysis to be
specified. Node voltages and inductor currents may be specified. A DC
solution is performed using the initial conditions as constraints. Note
that although inductors are normally treated as short circuits in the DC
solution in other SPICE programs, if an initial current is specified,
they are treated as infinite-impedance current sources in LTspice.
Syntax: .ic [V(<n1>)=<voltage>] [I(<inductor>)=<current>]
Example: .ic V(in)=2 V(out)=5 V(vc)=1.8 I(L1)=300m
"
It should probably be replaced by:
"
In LTspice, an .ic statement for a node voltage, e.g.,
.IC V(out1)=10 works(whether UIC is specified or not).
However, .ic I(L1) will never work in LTspice because I(L1)
is not a voltage. The only place LTspice accepts an IC for
a component is on the component.
"
Helmut, shouldn't this be corrected given what you found ..?
Cheers
AG
toggle quoted message
Show quoted text
Hello
--- Mike
In LTspice, an .ic statement for a node voltage, e.g.,
.IC V(out1)=10 works(whether UIC is specified or not).
However, .ic I(L1) will never work in LTspice because I(L1)
is not a voltage. The only place LTspice accepts and IC for
a component is on the component.
...
--- end
I don't know why Mike has chosen this definition, but I guess
he had a good reason to implement it this way.
Best regards,
Helmut
|
Re: Inductor initial conditions
--- In LTspice@..., "E.A.Neonakis" <eaneonakis@...> wrote:
Dear Mr Sennewald
May I ask what was intended in this case? Are there
circumstances that this differentiated behaviour between
initial capacitor voltages and inductor currents is useful?
Best Regards,
E.A.Neonakis
Hello --- Mike In LTspice, an .ic statement for a node voltage, e.g., .IC V(out1)=10 works(whether UIC is specified or not). However, .ic I(L1) will never work in LTspice because I(L1) is not a voltage. The only place LTspice accepts and IC for a component is on the component. ... --- end I don't know why Mike has chosen this definition, but I guess he had a good reason to implement it this way. Best regards, Helmut Helmut wrote:
.ic I(L1)=1 --> used
I have discussed this case with Mike in the last few hours.
Mike told me that the behavior of LTspice is as intended,
|
Re: Inductor initial conditions
Dear Mr Sennewald
May I ask what was intended in this case? Are there circumstances that this differentiated behaviour between initial capacitor voltages and inductor currents is useful?
Best Regards,
E.A.Neonakis
Helmut wrote:
toggle quoted message
Show quoted text
.ic I(L1)=1 --> used
I have discussed this case with Mike in the last few hours.
Mike told me that the behavior of LTspice is as intended,
|
Re: Some confusion about pass-transistor circuit
Jim Wagner wrote: Series is the usual connection used in CMOS gate output structures. It's new to me! I have never seen that kind of circuit connection before. Andy
|
