On Tuesday, January 2, 2024 at 4:26:54 PM UTC-6, Dan Purgert wrote:
> On 2024-01-02, john larkin wrote:
> > On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <d...@djph.net>
> > wrote:
> >
> >>Got it installed with wine here on my PC. Fonts are a bit wonky, but
> >>that happens from time to time, so not going to really bother with it.
> >>
> >>Took things for a spin by trying to build your basic low-pass filter as
> >>one might see on a momentary-contact button (etc.).
> >>
> >>Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I
> >>just blind, and missed them somewhere in the myriad of semi-cryptic
> >>parts, or is it just that they happen to not be modeled in the base
> >>product?
> >
> > There's a voltage-controlled switch SW. Ask HELP to search for
> > 'switch'.
> Yeah, I saw that. I was looking for "generic bogus button" type "switch"
> (not that sw or csw wouldn't work). I'll probably just work-around it
> by inserting one of the variable voltage sources I noticed (IIRC, one
> said it'd do square wave, I think).
> --
> |_|O|_|
> |_|_|O| Github: https://github.com/dpurgert
> |O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860
I was once bitten by the difference between a switch and a pulse voltage source.
The switch can close to supply the voltage, but, importantly, when it opens, it does not
short the input of your load like a source will. You could put a diode in series with a
pulsing voltage source to sort-of do the same as a switch, but then there is the diode
drop to consider. Just my $.02 dollars.
Reply by Phil Hobbs●January 2, 20242024-01-02
John Larkin <jl@997PotHill.com> wrote:
> On Tue, 02 Jan 2024 14:58:21 -0800, john larkin <jl@650pot.com> wrote:
>
>> On Tue, 02 Jan 2024 14:42:36 -0800, john larkin <jl@650pot.com> wrote:
>>
>>> On Tue, 2 Jan 2024 22:26:46 -0000 (UTC), Dan Purgert <dan@djph.net>
>>> wrote:
>>>
>>>> On 2024-01-02, john larkin wrote:
>>>>> On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net>
>>>>> wrote:
>>>>>
>>>>>> Got it installed with wine here on my PC. Fonts are a bit wonky, but
>>>>>> that happens from time to time, so not going to really bother with it.
>>>>>>
>>>>>> Took things for a spin by trying to build your basic low-pass filter as
>>>>>> one might see on a momentary-contact button (etc.).
>>>>>>
>>>>>> Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I
>>>>>> just blind, and missed them somewhere in the myriad of semi-cryptic
>>>>>> parts, or is it just that they happen to not be modeled in the base
>>>>>> product?
>>>>>
>>>>> There's a voltage-controlled switch SW. Ask HELP to search for
>>>>> 'switch'.
>>>>
>>>> Yeah, I saw that. I was looking for "generic bogus button" type "switch"
>>>> (not that sw or csw wouldn't work). I'll probably just work-around it
>>>> by inserting one of the variable voltage sources I noticed (IIRC, one
>>>> said it'd do square wave, I think).
>>>
>>> Yeah, the V voltage source (in "advanced" mode) has a pulse generator
>>> mode.
>>>
>>> I usually specify a rise and fall time. LT is a little weird if you
>>> use defaults.
>>>
>>> Note that if Tr=Tf=Ton=1, it's above zero for 3 seconds. Ton is the
>>> flat part.
>>
>> Sometimes it's handy to use a sine wave source and square it up with a
>> comparator. That makes square waves easier.
>>
>> An e with a tanh function makes a nice comparator.
>
> Not e, but BV. If node J is a sine wave, a BV with equation
>
> V = tanh(9K*V(J))
>
> makes a nice square wave.
>
> The lamented Jim Thompson turned me on to tanh.
>
>
The standard ltspice switch has a nice infinitely-differentiable
characteristic if you specify a negative hysteresis value. It’s an arctan
rather than tanh, but it works just as well.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC /
Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics
Reply by John Larkin●January 2, 20242024-01-02
On Tue, 02 Jan 2024 14:58:21 -0800, john larkin <jl@650pot.com> wrote:
>On Tue, 02 Jan 2024 14:42:36 -0800, john larkin <jl@650pot.com> wrote:
>
>>On Tue, 2 Jan 2024 22:26:46 -0000 (UTC), Dan Purgert <dan@djph.net>
>>wrote:
>>
>>>On 2024-01-02, john larkin wrote:
>>>> On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net>
>>>> wrote:
>>>>
>>>>>Got it installed with wine here on my PC. Fonts are a bit wonky, but
>>>>>that happens from time to time, so not going to really bother with it.
>>>>>
>>>>>Took things for a spin by trying to build your basic low-pass filter as
>>>>>one might see on a momentary-contact button (etc.).
>>>>>
>>>>>Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I
>>>>>just blind, and missed them somewhere in the myriad of semi-cryptic
>>>>>parts, or is it just that they happen to not be modeled in the base
>>>>>product?
>>>>
>>>> There's a voltage-controlled switch SW. Ask HELP to search for
>>>> 'switch'.
>>>
>>>Yeah, I saw that. I was looking for "generic bogus button" type "switch"
>>>(not that sw or csw wouldn't work). I'll probably just work-around it
>>>by inserting one of the variable voltage sources I noticed (IIRC, one
>>>said it'd do square wave, I think).
>>
>>Yeah, the V voltage source (in "advanced" mode) has a pulse generator
>>mode.
>>
>>I usually specify a rise and fall time. LT is a little weird if you
>>use defaults.
>>
>>Note that if Tr=Tf=Ton=1, it's above zero for 3 seconds. Ton is the
>>flat part.
>
>Sometimes it's handy to use a sine wave source and square it up with a
>comparator. That makes square waves easier.
>
>An e with a tanh function makes a nice comparator.
Not e, but BV. If node J is a sine wave, a BV with equation
V = tanh(9K*V(J))
makes a nice square wave.
The lamented Jim Thompson turned me on to tanh.
Reply by Dan Purgert●January 2, 20242024-01-02
On 2024-01-02, john larkin wrote:
> On Tue, 2 Jan 2024 22:26:46 -0000 (UTC), Dan Purgert <dan@djph.net>
> wrote:
>
>>On 2024-01-02, john larkin wrote:
>>> On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net>
>>> wrote:
>>>
>>>>Got it installed with wine here on my PC. Fonts are a bit wonky, but
>>>>that happens from time to time, so not going to really bother with it.
>>>>
>>>>Took things for a spin by trying to build your basic low-pass filter as
>>>>one might see on a momentary-contact button (etc.).
>>>>
>>>>Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I
>>>>just blind, and missed them somewhere in the myriad of semi-cryptic
>>>>parts, or is it just that they happen to not be modeled in the base
>>>>product?
>>>
>>> There's a voltage-controlled switch SW. Ask HELP to search for
>>> 'switch'.
>>
>>Yeah, I saw that. I was looking for "generic bogus button" type "switch"
>>(not that sw or csw wouldn't work). I'll probably just work-around it
>>by inserting one of the variable voltage sources I noticed (IIRC, one
>>said it'd do square wave, I think).
>
> Yeah, the V voltage source (in "advanced" mode) has a pulse generator
> mode.
>
> I usually specify a rise and fall time. LT is a little weird if you
> use defaults.
Yes, I'm starting to notice that :)
>
> Note that if Tr=Tf=Ton=1, it's above zero for 3 seconds. Ton is the
> flat part.
>
Thanks (and for the hint about comparators). Lots to learn here :)
--
|_|O|_|
|_|_|O| Github: https://github.com/dpurgert
|O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860
Reply by john larkin●January 2, 20242024-01-02
On Tue, 02 Jan 2024 14:42:36 -0800, john larkin <jl@650pot.com> wrote:
>On Tue, 2 Jan 2024 22:26:46 -0000 (UTC), Dan Purgert <dan@djph.net>
>wrote:
>
>>On 2024-01-02, john larkin wrote:
>>> On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net>
>>> wrote:
>>>
>>>>Got it installed with wine here on my PC. Fonts are a bit wonky, but
>>>>that happens from time to time, so not going to really bother with it.
>>>>
>>>>Took things for a spin by trying to build your basic low-pass filter as
>>>>one might see on a momentary-contact button (etc.).
>>>>
>>>>Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I
>>>>just blind, and missed them somewhere in the myriad of semi-cryptic
>>>>parts, or is it just that they happen to not be modeled in the base
>>>>product?
>>>
>>> There's a voltage-controlled switch SW. Ask HELP to search for
>>> 'switch'.
>>
>>Yeah, I saw that. I was looking for "generic bogus button" type "switch"
>>(not that sw or csw wouldn't work). I'll probably just work-around it
>>by inserting one of the variable voltage sources I noticed (IIRC, one
>>said it'd do square wave, I think).
>
>Yeah, the V voltage source (in "advanced" mode) has a pulse generator
>mode.
>
>I usually specify a rise and fall time. LT is a little weird if you
>use defaults.
>
>Note that if Tr=Tf=Ton=1, it's above zero for 3 seconds. Ton is the
>flat part.
Sometimes it's handy to use a sine wave source and square it up with a
comparator. That makes square waves easier.
An e with a tanh function makes a nice comparator.
Reply by john larkin●January 2, 20242024-01-02
On Tue, 2 Jan 2024 22:26:46 -0000 (UTC), Dan Purgert <dan@djph.net>
wrote:
>On 2024-01-02, john larkin wrote:
>> On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net>
>> wrote:
>>
>>>Got it installed with wine here on my PC. Fonts are a bit wonky, but
>>>that happens from time to time, so not going to really bother with it.
>>>
>>>Took things for a spin by trying to build your basic low-pass filter as
>>>one might see on a momentary-contact button (etc.).
>>>
>>>Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I
>>>just blind, and missed them somewhere in the myriad of semi-cryptic
>>>parts, or is it just that they happen to not be modeled in the base
>>>product?
>>
>> There's a voltage-controlled switch SW. Ask HELP to search for
>> 'switch'.
>
>Yeah, I saw that. I was looking for "generic bogus button" type "switch"
>(not that sw or csw wouldn't work). I'll probably just work-around it
>by inserting one of the variable voltage sources I noticed (IIRC, one
>said it'd do square wave, I think).
Yeah, the V voltage source (in "advanced" mode) has a pulse generator
mode.
I usually specify a rise and fall time. LT is a little weird if you
use defaults.
Note that if Tr=Tf=Ton=1, it's above zero for 3 seconds. Ton is the
flat part.
Reply by Dan Purgert●January 2, 20242024-01-02
On 2024-01-02, john larkin wrote:
> On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net>
> wrote:
>
>>Got it installed with wine here on my PC. Fonts are a bit wonky, but
>>that happens from time to time, so not going to really bother with it.
>>
>>Took things for a spin by trying to build your basic low-pass filter as
>>one might see on a momentary-contact button (etc.).
>>
>>Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I
>>just blind, and missed them somewhere in the myriad of semi-cryptic
>>parts, or is it just that they happen to not be modeled in the base
>>product?
>
> There's a voltage-controlled switch SW. Ask HELP to search for
> 'switch'.
Yeah, I saw that. I was looking for "generic bogus button" type "switch"
(not that sw or csw wouldn't work). I'll probably just work-around it
by inserting one of the variable voltage sources I noticed (IIRC, one
said it'd do square wave, I think).
--
|_|O|_|
|_|_|O| Github: https://github.com/dpurgert
|O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860
Reply by john larkin●January 2, 20242024-01-02
On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net>
wrote:
>Got it installed with wine here on my PC. Fonts are a bit wonky, but
>that happens from time to time, so not going to really bother with it.
>
>Took things for a spin by trying to build your basic low-pass filter as
>one might see on a momentary-contact button (etc.).
>
>Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I
>just blind, and missed them somewhere in the myriad of semi-cryptic
>parts, or is it just that they happen to not be modeled in the base
>product?
There's a voltage-controlled switch SW. Ask HELP to search for
'switch'.
S is in the index too.
In the component selector, search for SW. It needs a .model statement.
Use a voltage source to switch it.
Or just poke a voltage source into your filter. Or use a voltage
source and a mosfet.
Reply by Lasse Langwadt Christensen●January 2, 20242024-01-02
tirsdag den 2. januar 2024 kl. 22.17.33 UTC+1 skrev Dan Purgert:
> Got it installed with wine here on my PC. Fonts are a bit wonky, but
> that happens from time to time, so not going to really bother with it.
>
> Took things for a spin by trying to build your basic low-pass filter as
> one might see on a momentary-contact button (etc.).
>
> Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I
> just blind, and missed them somewhere in the myriad of semi-cryptic
> parts, or is it just that they happen to not be modeled in the base
> product?
Got it installed with wine here on my PC. Fonts are a bit wonky, but
that happens from time to time, so not going to really bother with it.
Took things for a spin by trying to build your basic low-pass filter as
one might see on a momentary-contact button (etc.).
Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I
just blind, and missed them somewhere in the myriad of semi-cryptic
parts, or is it just that they happen to not be modeled in the base
product?
--
|_|O|_|
|_|_|O| Github: https://github.com/dpurgert
|O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860