开云体育

  1. LTspice
  2. Messages
Expanded Topics Messages Polls
Date
Re: Incandescent lamp model

 

I think I am finished for the day.?
I rewrote the device file using just a resistor and some equations, but I can't get passed this error "can't resolve .param r=rstart*(1+alpha*(t-tstart))".?
?
Files are in temp "LampModel-RA.zip".
Re: Incandescent lamp model

 

开云体育

The difficult bit is deriving the temperature from the applied voltage, or? the filament current. However, I think you can use a 'backwards'? trick, by defining the temperature as the initial condition. It should be well above room temperature, but not so high that the filament glows. Try 300 C. I posted some data about the tempco of tungsten a few days ago, which gives you alpha.? Using the equation R=Rcold?(1+alpha?(T?Tcold)), with R0 = room temperature resistance and To is room temperature you can get R at T = 300 C.

On 2025-03-17 23:26, Richard Andrews via groups.io wrote:
I put this together. Hope you need it.
?
R0 = lamp voltage rating^2 / power rating
T0 = start temp
T = temp
alpha = temp coefficient of tungsten/filament material
?
R=R0?(1+alpha?(T?T0))
--
OOO - Own Opinions only If something is true: * as far as we know - it's science *for certain - it's mathematics *unquestionably - it's religion

Virus-free.
Re: Use a TABLE function in a BV to make a custom defined function.

 

Andy
AWESOME !!! ?It works !!
Thank you so very much!
?
So weird that the text function creates a net, so I just mats a net with the OUT4 name and can probe that.
?
This will be useful!
?
Thank you!
JD
Re: Incandescent lamp model

 

I put this together. Hope you need it.
?
R0 = lamp voltage rating^2 / power rating
T0 = start temp
T = temp
alpha = temp coefficient of tungsten/filament material
?
R=R0?(1+alpha?(T?T0))
Re: Incandescent lamp model

 

If you model a filament lamp, I am learning you can model it as a resistor with a defined power capability.
Re: MAX9939 is there any model available for LTspice ?

[email protected]
 

Good point, I just did now :-)
Re: Incandescent lamp model

 

开云体育

Yes, the low Q of the Wien bridge is not good for low distortion. I intend to try out that MFB circuit when I get a chance.

On 2025-03-17 21:45, Tony Casey wrote:
Perhaps you'd entertain a non-Wien Bridge oscillator: MFB_Oscillator. A working example sine wave oscillator schematic using an MFB (multiple feedback) topology. It uses no more parts than the usual Wien bridge and offers significantly better (distortion) performance.
?
--
Regards,
Tony


On 17/03/2025 20:33, Bell, Dave via groups.io wrote:

I was trying for the “classical” hardware implementation (cf. HP201C, e.g.)

?

I got a LTspice model working well, using a diode and filter feedback to adjust a behavioral resistor, but that’s cheating.


--
OOO - Own Opinions only If something is true: * as far as we know - it's science *for certain - it's mathematics *unquestionably - it's religion

Virus-free.
Re: MAX9939 is there any model available for LTspice ?

 

开云体育

Have you asked ADI for one?

On 2025-03-17 21:42, Michael.Baus via groups.io wrote:
Thanks for your help!
--
OOO - Own Opinions only If something is true: * as far as we know - it's science *for certain - it's mathematics *unquestionably - it's religion

Virus-free.
Re: Incandescent lamp model

 

Is there a reason to adapt this file to your needs? You may want to start from scratch.
?
I read a good discussion here:

MAX9939 is there any model available for LTspice ?

[email protected]
 

Thanks for your help!
Re: Incandescent lamp model

 

开云体育

Perhaps you'd entertain a non-Wien Bridge oscillator: MFB_Oscillator. A working example sine wave oscillator schematic using an MFB (multiple feedback) topology. It uses no more parts than the usual Wien bridge and offers significantly better (distortion) performance.
?
--
Regards,
Tony


On 17/03/2025 20:33, Bell, Dave via groups.io wrote:

I was trying for the “classical” hardware implementation (cf. HP201C, e.g.)

?

I got a LTspice model working well, using a diode and filter feedback to adjust a behavioral resistor, but that’s cheating.
Re: Incandescent lamp model

 

开云体育

That sort of error is likely to be flagged by all versions of LTspice. I suggest you examine your .ASC carefully to see if you? can see an error. I suppose you have not added a model as text in the .ASC and also called it with an ',NC or .LIB directive?

On 2025-03-17 20:11, Bell, Dave via groups.io wrote:

Was this from the Lamp Test.asc in the zip file?

I didn’t have any errors from that, with XVII

?

From: [email protected] <[email protected]> On Behalf Of Richard Andrews via groups.io
Sent: Monday, March 17, 2025 1:06 PM
To: [email protected]
Subject: EXTERNAL: Re: [LTspice] Incandescent lamp model

?

DS1 is the name of the lamp you are testing as per the schematic.?

?

When I try to get an expanded listing I get "Fatal Error: Multiple instances of "B:ds1:cf"".

?

Mind you, I use LTspice 4.

--
OOO - Own Opinions only If something is true: * as far as we know - it's science *for certain - it's mathematics *unquestionably - it's religion

Virus-free.
Re: Incandescent lamp model

 

I have version XVII. I'll work from that.
Re: Incandescent lamp model

 

开云体育

Was this from the Lamp Test.asc in the zip file?

I didn’t have any errors from that, with XVII

?

From: [email protected] <[email protected]> On Behalf Of Richard Andrews via groups.io
Sent: Monday, March 17, 2025 1:06 PM
To: [email protected]
Subject: EXTERNAL: Re: [LTspice] Incandescent lamp model

?

DS1 is the name of the lamp you are testing as per the schematic.?

?

When I try to get an expanded listing I get "Fatal Error: Multiple instances of "B:ds1:cf"".

?

Mind you, I use LTspice 4.
Re: Incandescent lamp model

 

DS1 is the name of the lamp you are testing as per the schematic.?
?
When I try to get an expanded listing I get "Fatal Error: Multiple instances of "B:ds1:cf"".
?
Mind you, I use LTspice 4.
Re: Incandescent lamp model

 

开云体育

LOL!? 4X the hits with the wrong spelling

?

From: [email protected] <[email protected]> On Behalf Of Andy I via groups.io
Sent: Monday, March 17, 2025 12:31 PM
To: [email protected]
Subject: EXTERNAL: Re: [LTspice] Incandescent lamp model

?

Might try searching for "Wien Bridge".? And the incorrect spelling with "Wein".
Re: Incandescent lamp model

 

开云体育

I was trying for the “classical” hardware implementation (cf. HP201C, e.g.)

?

I got a LTspice model working well, using a diode and filter feedback to adjust a behavioral resistor, but that’s cheating.

?

From: [email protected] <[email protected]> On Behalf Of John Woodgate
Sent: Monday, March 17, 2025 12:22 PM
To: [email protected]
Subject: EXTERNAL: Re: [LTspice] Incandescent lamp model

?

That model is probably for a gas-filled lamp, but a pilot light is probably a vacuum lamp. That could make quite a difference. I'm surprised that a 6 V 10mA lamp is still made. Do you really need low distortion? Diode clipping can get down to about 1% with careful design. A JFET as a voltage-controlled resistor (VCR) can do better, but only for a one-off, because the FETs vary too much unless you use a very costly part designed and selected as a VCR.

On 2025-03-17 18:39, Bell, Dave via groups.io wrote:

I’m trying to adapt and use the model in LampModel.zip, uploaded by analogspiceman last September.

?

The test circuit supplied works fine for a 120VAC lamp.

I want to adapt it to a small pilot lamp, as a stabilizer for a Wein network oscillator.

?

There are a number of parameters defined in the model, but except foe ambient temperature, not well explained.

I commented the .param block and passed them externally, and that works exactly the same, as expected.

?

Now, can anyone suggest what needs “tuning”, to get? about 600 ohms at 10mA, after warm-up?

Ka, ambient temp (Kelvin) is easy.

Kc looks like design voltage (120RMS), but doesn’t really act like it; left alone.

Kf seems to be a heat transfer coefficient, maybe good for warmup timing, but slightly changes stable resistance.

CTf is a coupling factor from Tambient to Tfilament, sets warmup timing; left alone.

RTf is filament resistance, but changing that parameter makes only a very small difference to the preset, ~150 ohms.

?

Thanks,

Dave

--
OOO - Own Opinions only If something is true: * as far as we know - it's science *for certain - it's mathematics *unquestionably - it's religion

?

Virus-free.

Re: Incandescent lamp model

 

Might try searching for "Wien Bridge".? And the incorrect spelling with "Wein".
Re: Incandescent lamp model

 

开云体育

Where did I have DS1 ?

?

From: [email protected] <[email protected]> On Behalf Of Richard Andrews via groups.io
Sent: Monday, March 17, 2025 12:24 PM
To: [email protected]
Subject: EXTERNAL: Re: [LTspice] Incandescent lamp model

?

Is "DS1" an actual part number? I see it as a HID xenon lamp.
Re: Incandescent lamp model

 

开云体育

I searched for “incandescent”…

?

“lamp” returns 76 hits, such as clamp, differentialamp, CFL-lamp, Koren tubes, and my favorite:

“Electrical Pulsing of a Laser Diode for Usage in Fluorescence Microscopy.pdf??? ??Report File

Master of Science Thesis with LTspice simulation of step recovery diode and laser diode circuits”

?

?

?

From: [email protected] <[email protected]> On Behalf Of Andy I via groups.io
Sent: Monday, March 17, 2025 12:09 PM
To: [email protected]
Subject: EXTERNAL: Re: [LTspice] Incandescent lamp model

?

Just FYI -

?

There must be several more incandescent models here in this group.? Others have simulated with them in Wien Bridge oscillators.? But Analogspiceman's models are quite good quality so it's a good place - but not the only one - to start.

?

Andy
1161 - 1180 of 157653