Re: [volt-nuts] Redrafted schematic of Fluke 732A reference circuit

[roman]

I tried that some time ago but, not surprisingly, the model didn't behave quite 
the same as the real thing in the lab. I concluded )to myself, only!) that chip 
self-heating and thermal coupling between the two devices was the stumbling 
block. Then after I sent the question to you yesterday, I did a bit of idle 
googling and came across this
bbs.38hot.net/thread-105042-1-1.html
(Not sure if the url pasted correctly...here are the salient bits

"Hello fellow forum users,

I just finished with a telephone conversation with Bob Dobkin, and he was short 
on time, so I was not able to get all of the answers to every question I [and 
we] had, but here are the ones I was able to get:


5) They *could* make a model for LTspice, but the temperature effects are very 
difficult to simulate, and the market need is not large enough to support the 
development effort [my words].  He said the best way is to build the circuit 
and test it out in real life.
,,,"

Anyway, good job.  I don't have a 732A, but am looking to get more than I paid 
for out of a 332B which happens to have had its RefAmp replaced with an LTFLU 
(before I got it). I am looking at your circuit now as food for a bit of 
improvement, perhaps...
Roman


-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of David C. 
Partridge
Sent: Tuesday, 23 January 2018 10:03 PM
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] Redrafted schematic of Fluke 732A reference circuit

It's nothing fancy just a glom of a 2n3904 and a 6.2V Zener wrapped up in 
.subckt/.ends and makes no claim to a an accurate model (I somehow doubt that 
either Fluke or LT would be willing to share that).

** LTFLU **
*
* NI Multisim to SPICE Netlist Export
* Generated by: amonra
* Sat, Jan 20, 2018 15:16:41
*
.SUBCKT LTFLU C B EK A

*## Multisim Component LFLUD1 ##*
xLFLUD1 A EK BZX84B6V2LT1/ON__ZENER__1

*## Multisim Component LFLUQ1 ##*
qLFLUQ1 C B EK 2N3904__BJT_NPN__1


.SUBCKT BZX84B6V2LT1/ON__ZENER__1 2 1
**
*  Model Generated by MODPEX *
*Copyright(c) Symmetry Design Systems*
* All Rights Reserved*
*UNPUBLISHED LICENSED SOFTWARE   *
*   Contains Proprietary Information *
*  Which is The Property of  *
* SYMMETRY OR ITS LICENSORS  *
*Commercial Use or Resale Restricted *
*   by Symmetry License Agreement*
**
* Model generated on Dec 11, 03
* MODEL FORMAT: PSpice
* anode cathode
*node: 2  1
*Forward Section
D1 2 1 MD1
.MODEL MD1 D IS=5.21532e-16 N=1 XTI=1 RS=0.5
+ CJO=9.5e-11 TT=1e-08
*Leakage Current
R 1 2 MDR 2e+07 
.MODEL MDR RES TC1=0 TC2=0
*Breakdown
IZG 4 2 0.12
R4 4 2 300
D3 2 4 MD3
.MODEL MD3 D IS=2.5e-12 N=0.37046 XTI=0 EG=0.1
D2 5 4 MD2
.MODEL MD2 D IS=2.5e-12 N=1.16158 XTI=0 EG=0.1
EV1 1 5 6 0 1
IBV 0 6 0.001
RBV 6 0 MDRBV 5792.79
.MODEL MDRBV RES TC1=0.000353198
*-- PSpice DIODE MODEL DEFAULT PARAMETER
*  VALUES ARE ASSUMED
*IS=1E-14 RS=0 N=1 TT=0 CJO=0
*VJ=1 M=0.5 EG=1.11 XTI=3 FC=0.5
*KF=0 AF=1 BV=inf IBV=1e-3 TNOM=27
.ENDS bzx84b6v2lt1

.MODEL 2N3904__BJT_NPN__1   NPN(Is=6.734f Xti=3 Eg=1.11 Vaf=74.03 Bf=416.4 
Ne=1.259
+   Ise=6.734f Ikf=66.78m Xtb=1.5 Br=.7371 Nc=2 Isc=0 Ikr=0 Rc=1
+   Cjc=3.638p Mjc=.3085 Vjc=.75 Fc=.5 Cje=4.493p Mje=.2593 Vje=.75
+   Tr=239.5n Tf=301.2p Itf=.4 Vtf=4 Xtf=2 Rb=10)
.ENDS LTFLU 



-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of romeo987
Sent: 23 January 2018 10:31
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Redrafted schematic of Fluke 732A reference circuit

David,
Thank you for that - much easier to follow. I infer from this that you have a 
Spice model for the LTFLU. Can you elaborate, please?
Roman

> On 22 Jan 2018, at 2:15 pm, David C. Partridge 
> <david.partri...@perdrix.co.uk> wrote:
> 
> OK folks here's another location for anyone who can't get it from eevblog.com:
> 
> <http://www.perdrix.co.uk/manuals/Fluke%20732A%20Reference%20Circuit.p
> df>
> 
> Dave
> 
> -Original Message-
> From: volt-nuts
> [mailto:volt-nuts-bounces+david.partridge=perdrix.co...@febo.com] On 
> Behalf Of m k
> Sent: 21 January 2018 22:29
> To: Bob Albert; Discussion of precise voltage measurement
> Subject: Re: [volt-nuts] Redrafted schematic of Fluke 732A reference 
> circuit
> 
>> you possibly need to be logged into eevblog at the same time as you follow 
>> the link?
> ___
> volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> and follow the instructions there.
> 
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Re: [volt-nuts] Redrafted schematic of Fluke 732A reference circuit

[David C. Partridge]

It's nothing fancy just a glom of a 2n3904 and a 6.2V Zener wrapped up in 
.subckt/.ends and makes no claim to a an accurate model (I somehow doubt that 
either Fluke or LT would be willing to share that).

** LTFLU **
* 
* NI Multisim to SPICE Netlist Export
* Generated by: amonra
* Sat, Jan 20, 2018 15:16:41 
*
.SUBCKT LTFLU C B EK A

*## Multisim Component LFLUD1 ##*
xLFLUD1 A EK BZX84B6V2LT1/ON__ZENER__1

*## Multisim Component LFLUQ1 ##*
qLFLUQ1 C B EK 2N3904__BJT_NPN__1


.SUBCKT BZX84B6V2LT1/ON__ZENER__1 2 1
**
*  Model Generated by MODPEX *
*Copyright(c) Symmetry Design Systems*
* All Rights Reserved*
*UNPUBLISHED LICENSED SOFTWARE   *
*   Contains Proprietary Information *
*  Which is The Property of  *
* SYMMETRY OR ITS LICENSORS  *
*Commercial Use or Resale Restricted *
*   by Symmetry License Agreement*
**
* Model generated on Dec 11, 03
* MODEL FORMAT: PSpice
* anode cathode
*node: 2  1
*Forward Section
D1 2 1 MD1
.MODEL MD1 D IS=5.21532e-16 N=1 XTI=1 RS=0.5
+ CJO=9.5e-11 TT=1e-08
*Leakage Current
R 1 2 MDR 2e+07 
.MODEL MDR RES TC1=0 TC2=0
*Breakdown
IZG 4 2 0.12
R4 4 2 300
D3 2 4 MD3
.MODEL MD3 D IS=2.5e-12 N=0.37046 XTI=0 EG=0.1
D2 5 4 MD2
.MODEL MD2 D IS=2.5e-12 N=1.16158 XTI=0 EG=0.1
EV1 1 5 6 0 1
IBV 0 6 0.001
RBV 6 0 MDRBV 5792.79
.MODEL MDRBV RES TC1=0.000353198
*-- PSpice DIODE MODEL DEFAULT PARAMETER
*  VALUES ARE ASSUMED
*IS=1E-14 RS=0 N=1 TT=0 CJO=0
*VJ=1 M=0.5 EG=1.11 XTI=3 FC=0.5
*KF=0 AF=1 BV=inf IBV=1e-3 TNOM=27
.ENDS bzx84b6v2lt1

.MODEL 2N3904__BJT_NPN__1   NPN(Is=6.734f Xti=3 Eg=1.11 Vaf=74.03 Bf=416.4 
Ne=1.259
+   Ise=6.734f Ikf=66.78m Xtb=1.5 Br=.7371 Nc=2 Isc=0 Ikr=0 Rc=1
+   Cjc=3.638p Mjc=.3085 Vjc=.75 Fc=.5 Cje=4.493p Mje=.2593 Vje=.75
+   Tr=239.5n Tf=301.2p Itf=.4 Vtf=4 Xtf=2 Rb=10)
.ENDS LTFLU 



-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of romeo987
Sent: 23 January 2018 10:31
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Redrafted schematic of Fluke 732A reference circuit

David,
Thank you for that - much easier to follow. I infer from this that you have a 
Spice model for the LTFLU. Can you elaborate, please?
Roman

> On 22 Jan 2018, at 2:15 pm, David C. Partridge 
> <david.partri...@perdrix.co.uk> wrote:
> 
> OK folks here's another location for anyone who can't get it from eevblog.com:
> 
> <http://www.perdrix.co.uk/manuals/Fluke%20732A%20Reference%20Circuit.p
> df>
> 
> Dave
> 
> -Original Message-
> From: volt-nuts 
> [mailto:volt-nuts-bounces+david.partridge=perdrix.co...@febo.com] On 
> Behalf Of m k
> Sent: 21 January 2018 22:29
> To: Bob Albert; Discussion of precise voltage measurement
> Subject: Re: [volt-nuts] Redrafted schematic of Fluke 732A reference 
> circuit
> 
>> you possibly need to be logged into eevblog at the same time as you follow 
>> the link?
> ___
> volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> and follow the instructions there.
> 
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> and follow the instructions there.

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Re: [volt-nuts] Redrafted schematic of Fluke 732A reference circuit

[David C. Partridge]

OK folks here's another location for anyone who can't get it from eevblog.com:

<http://www.perdrix.co.uk/manuals/Fluke%20732A%20Reference%20Circuit.pdf>

Dave

-Original Message-
From: volt-nuts 
[mailto:volt-nuts-bounces+david.partridge=perdrix.co...@febo.com] On Behalf Of 
m k
Sent: 21 January 2018 22:29
To: Bob Albert; Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Redrafted schematic of Fluke 732A reference circuit

> you possibly need to be logged into eevblog at the same time as you follow 
> the link?
___
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Re: [volt-nuts] Redrafted schematic of Fluke 732A reference circuit

[m k]

On 21/01/2018 18:27, Bob Albert via volt-nuts wrote:
>   I can't seem to make the link work.
> Bob
>  On Sunday, January 21, 2018, 9:49:32 AM PST, David C. Partridge 
>  wrote:
>   
>   Darn the URL got split:
>
> 
>
> Dave
>
> -Original Message-
> From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of David C. 
> Partridge
> Sent: 21 January 2018 17:44
> To: 'Discussion of precise voltage measurement'
> Subject: [volt-nuts] Redrafted schematic of Fluke 732A reference circuit
>
> I have redrafted the schematic for the Reference Circuit on the A5 board 
> using "normal conventions" so it should be easier to understand.
>
> I've included the components that are hosted on the A4 board for clarity.
> Q2 acts as current limiter.
>
> The file is a little large so you can find it here:
> ...
>
> HtH
> Dave Partridge
you possibly need to be logged into eevblog at the same time as you follow the 
link?
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Re: [volt-nuts] Redrafted schematic of Fluke 732A reference circuit

[Bob Albert via volt-nuts]

 I can't seem to make the link work.
Bob
On Sunday, January 21, 2018, 9:49:32 AM PST, David C. Partridge 
 wrote:  
 
 Darn the URL got split:



Dave

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of David C. 
Partridge
Sent: 21 January 2018 17:44
To: 'Discussion of precise voltage measurement'
Subject: [volt-nuts] Redrafted schematic of Fluke 732A reference circuit

I have redrafted the schematic for the Reference Circuit on the A5 board using 
"normal conventions" so it should be easier to understand.

I've included the components that are hosted on the A4 board for clarity.
Q2 acts as current limiter.

The file is a little large so you can find it here:


HtH
Dave Partridge


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Re: [volt-nuts] Redrafted schematic of Fluke 732A reference circuit

[David C. Partridge]

Darn the URL got split:



Dave

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of David C. 
Partridge
Sent: 21 January 2018 17:44
To: 'Discussion of precise voltage measurement'
Subject: [volt-nuts] Redrafted schematic of Fluke 732A reference circuit

I have redrafted the schematic for the Reference Circuit on the A5 board using 
"normal conventions" so it should be easier to understand.

I've included the components that are hosted on the A4 board for clarity.
Q2 acts as current limiter.

The file is a little large so you can find it here:


HtH
Dave Partridge


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