On Friday, November 14, 2014 11:31:40 PM UTC-5, Jasen Betts wrote:
> On 2014-11-14, dakupoto@gmail.com <dakupoto@gmail.com> wrote:
> 
> > home(the simulations were done in my
> > spare time), both of which use text
> > based source files as input, as opposed
> > to LTSpice's GUI based format.
> 
> unfortunately (for you) LTSpice has become the lingua franca 
> for sharing simulations in this newsgroup, mainly because the
> price is right *1, it'll run on anything *2 and it's easier 
> to use than ms-paint *3
> 
> The save format is an ASCII *4 netlist with some embedded GUI 
> layout information, it can run other ASCII netlists.
> 
> *1 Free download
> 
> *2 Well, anyting with an x86 cpu - it runs OK in wine, and
> whatever it is that recent macs use to run windows apps
> 
> *3 if your goal is drawing electronic schematics
> 
> *4 If you tell it to use 'u' for micro, there's a checkbox 
> somewhere,else Windows-1252.
> 
> -- 
> umop apisdn

Ngspice is completely free, and has its own
users' and developers forums on SourceForge.
Though initially developed for Unix-like and
Linux platforms, precompiled binaries are 
available for Windows -- no issues at all. 
No need to install Wine, Linux/Unix is its 
native environment. Output files can be 
plotted with Excel or OpenOffice or Gnuplot.
The text based input makes it very easy to 
include special models -- about 2 years ago,
I had to do a lot of work with the sub-micron
MOSFET models from UC Berkeley(BSIM 4.6) --
all I had to do was have an .INCLUDE statement
in my source files.

On Friday, November 14, 2014 10:56:07 PM UTC-5, meow...@care2.com wrote:
> On Friday, November 14, 2014 4:58:46 AM UTC, daku...@gmail.com wrote:
> > On Thursday, November 13, 2014 7:02:01 AM UTC-5, Ian Malcolm wrote:
> > > dakupoto@gmail.com wrote in
> > > news:74eddd6b-53e9-4bac-b29d-5cc40e3544a1@googlegroups.com:=20
> > >=20
> > > > Could some electronics guru please shed some light=20
> > > > on this ? Several Web sites(please check list below)
> > > > have schematics and flashy color photographs of=20
> > > > single white led light powered off a single 1.5 Volt=20
> > > > AA battery.
> > > > http://cappels.org/dproj/ledpage/leddrv.htm
> > > > http://www.electroschematics.com/6195/high-efficiency-led-with-1-5-=
volt
> > > > s/=20
> > > > dinspirations.com/appliedcontent/Projects/Proj-WhiteLEDDrvr/Proj-Wh=
iteL
> > > > EDDrvr.html As most of these are very simple, I have simulated=20
> > > > a number of them with SPICE, but none of them=20
> > > > produce the advertised results. What is the mystery ?
> > > > Some even have supposed oscilloscope traces !! Any=20
> > > > thoughts hints would be helpful. Thanks in advance.
> > >=20
> > > This class of single transistor blocking oscillator boost converter=
=20
> > > designed to drive a LED from a single cell is colloquially known as a=
=20
> > > "Joule Thief".   Searching for that term with the keywords 'SPICE=20
> > > simulation' will find many simulations of varying degrees of accuracy=
. =20
> > > The basic circuit is pretty forgiving, and can easily be got working =
with=20
> > > junk-box parts which accounts for its popularity.
> > >=20
> > > If the simulation doesn't model non-ideal behaviour of key components=
 to=20
> > > a reasonable level of accuracy, it will *NOT* produce realistic resul=
ts.
> > > Have you accounted for the cell's internal resistance, the resistance=
 of=20
> > > the transformer primary, transformer core saturation, the LED's junct=
ion=20
> > > capacitance and the transistor's gain falling at high collector curre=
nts?
> > >=20
> > > Post your simulations (preferably in LTSPICE format) and the observed=
=20
> > > results you are trying to match up with and chances are, someone will=
=20
> > > point out what you've missed.
> > >=20
> > > --=20
> > > Ian Malcolm.   London, ENGLAND.  (NEWSGROUP REPLY PREFERRED)=20
> > > ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk=20
> > > [at]=3D@, [dash]=3D- & [dot]=3D. *Warning* HTML & >32K emails --> NUL
> >=20
> > Yes, I agree totally that unless the non-linearities in the key inducto=
r=20
> > behavior are modeled correctly, the=20
> > SPICE simulation would work. As for=20
> > the transistor, I have used the standard
> > SPICE model for 2N4401. The diode=20
> > has not yet been inserted. I was just
> > trying to see if the oscillations could=20
> > be simulated first. Unfortunately, I=20
> > use HSpice at work, and Ngspice at=20
> > home(the simulations were done in my
> > spare time), both of which use text
> > based source files as input, as opposed
> > to LTSpice's GUI based format.
>=20
> LT does the textfile format too
>=20
>=20
> NT

Well,
The source file is below. It runs on Ngspice-26.
The inductor is non-ideal, and the model for white light LED is also includ=
ed. As shown below, I have tried to measure current and voltage, and hence =
the three current measurement
nodes. The circuit is a minor variation of one
I saw at one of the Web sites I referred to, in=20
my initial post.

.PARAMETERS PI=3D3.14 PERMFS=3D0.000001256 RELPERM=3D500
.PARAMETERS NUMT=3D50 RAD=3D0.005 LEN=3D0.018825 CAPVALNOM=3D0.00001

.MODEL 2N4401 NPN(IS=3D1.75E-12 ISE=3D5.92E-14 ISC=3D9.42E-14 XTI=3D3.00 BF=
=3D3.03E2 BR=3D1.00E-2 IKF=3D2.11E-1 IKR=3D1.00 XTB=3D1.5 VAF=3D3.60E2 VAR=
=3D1.64E1 VJE=3D3.00E-1 VJC=3D3.00E-1 RE=3D1.00E-2 RC=3D1.07 RB=3D8.63E1 RB=
M=3D1.00E-2 IRB=3D9.62E-3 CJE=3D2.64E-11 CJC=3D1.37E-11 XCJC=3D1.00 FC=3D5.=
00E-1 NF=3D1.10 NR=3D1.71 NE=3D1.26 NC=3D1.00 MJE=3D4.09E-1 MJC=3D4.89E-1 T=
F=3D5.16E-10 TR=3D233.7E-9 PTF=3D0 ITF=3D5.09E-1 VTF=3D1.09E5 XTF=3D1.64 EG=
=3D1.11 KF=3D1E-9 AF=3D1)

.MODEL NSPW500BS D(Is=3D0.27n Rs=3D5.65 N=3D6.79 Cjo=3D42p Iave=3D30m Vpk=
=3D5)

.SUBCKT NIINDUCTOR 1 2
* 1 IN
* 2 OUT
C0 1 2 0.75nF
L0 1 3 L=3D'RELPERM*PERMFS*NUMT*NUMT*PI*RAD*RAD/LEN'
R0 3 2 1.5
.ENDS

D0 9 0 NSPW500BS
XL0 3 4 NIINDUCTOR
XL1 3 9 NIINDUCTOR
Q0 6 7 0 2N4401
R0 1 2 1
R1 4 5 1
R2 7 8 0.1

VP 1 0 DC 1.5 AC 0.0
VTST1 2 3 DC 0.0 AC 0.0
VTST2 5 6 DC 0.0 AC 0.0
VTST3 8 9 DC 0.0 AC 0.0

.OPTIONS METHOD=3DGEAR NOPAGE
.IC V(2)=3D0.0 V(3)=3D0.0 V(4)=3D0.0 V(5)=3D0.0
+ V(6)=3D0.0 V(7)=3D0.0 V(8)=3D0.0 V(9)=3D0.0
.TRAN 20.0ms 2000.0ms 5.0ms UIC
.PRINT TRAN V(6)
.END

On Friday, November 14, 2014 4:58:46 AM UTC, daku...@gmail.com wrote:
> On Thursday, November 13, 2014 7:02:01 AM UTC-5, Ian Malcolm wrote:
> > dakupoto@gmail.com wrote in
> > news:74eddd6b-53e9-4bac-b29d-5cc40e3544a1@googlegroups.com: 
> > 
> > > Could some electronics guru please shed some light 
> > > on this ? Several Web sites(please check list below)
> > > have schematics and flashy color photographs of 
> > > single white led light powered off a single 1.5 Volt 
> > > AA battery.
> > > http://cappels.org/dproj/ledpage/leddrv.htm
> > > http://www.electroschematics.com/6195/high-efficiency-led-with-1-5-volt
> > > s/ 
> > > dinspirations.com/appliedcontent/Projects/Proj-WhiteLEDDrvr/Proj-WhiteL
> > > EDDrvr.html As most of these are very simple, I have simulated 
> > > a number of them with SPICE, but none of them 
> > > produce the advertised results. What is the mystery ?
> > > Some even have supposed oscilloscope traces !! Any 
> > > thoughts hints would be helpful. Thanks in advance.
> > 
> > This class of single transistor blocking oscillator boost converter 
> > designed to drive a LED from a single cell is colloquially known as a 
> > "Joule Thief".   Searching for that term with the keywords 'SPICE 
> > simulation' will find many simulations of varying degrees of accuracy.  
> > The basic circuit is pretty forgiving, and can easily be got working with 
> > junk-box parts which accounts for its popularity.
> > 
> > If the simulation doesn't model non-ideal behaviour of key components to 
> > a reasonable level of accuracy, it will *NOT* produce realistic results.
> > Have you accounted for the cell's internal resistance, the resistance of 
> > the transformer primary, transformer core saturation, the LED's junction 
> > capacitance and the transistor's gain falling at high collector currents?
> > 
> > Post your simulations (preferably in LTSPICE format) and the observed 
> > results you are trying to match up with and chances are, someone will 
> > point out what you've missed.
> > 
> > -- 
> > Ian Malcolm.   London, ENGLAND.  (NEWSGROUP REPLY PREFERRED) 
> > ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk 
> > [at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL
> 
> Yes, I agree totally that unless the non-linearities in the key inductor 
> behavior are modeled correctly, the 
> SPICE simulation would work. As for 
> the transistor, I have used the standard
> SPICE model for 2N4401. The diode 
> has not yet been inserted. I was just
> trying to see if the oscillations could 
> be simulated first. Unfortunately, I 
> use HSpice at work, and Ngspice at 
> home(the simulations were done in my
> spare time), both of which use text
> based source files as input, as opposed
> to LTSpice's GUI based format.

LT does the textfile format too


NT

On 2014-11-14, dakupoto@gmail.com <dakupoto@gmail.com> wrote:

> home(the simulations were done in my
> spare time), both of which use text
> based source files as input, as opposed
> to LTSpice's GUI based format.

unfortunately (for you) LTSpice has become the lingua franca 
for sharing simulations in this newsgroup, mainly because the
price is right *1, it'll run on anything *2 and it's easier 
to use than ms-paint *3

The save format is an ASCII *4 netlist with some embedded GUI 
layout information, it can run other ASCII netlists.

*1 Free download

*2 Well, anyting with an x86 cpu - it runs OK in wine, and
whatever it is that recent macs use to run windows apps

*3 if your goal is drawing electronic schematics

*4 If you tell it to use 'u' for micro, there's a checkbox 
somewhere,else Windows-1252.

-- 
umop apisdn

On Thursday, November 13, 2014 5:45:56 PM UTC-5, Robert Baer wrote:
> dakupoto@gmail.com wrote:
> > Could some electronics guru please shed some light
> > on this ? Several Web sites(please check list below)
> > have schematics and flashy color photographs of
> > single white led light powered off a single 1.5 Volt
> > AA battery.
> > http://cappels.org/dproj/ledpage/leddrv.htm
> > http://www.electroschematics.com/6195/high-efficiency-led-with-1-5-volts/
> > dinspirations.com/appliedcontent/Projects/Proj-WhiteLEDDrvr/Proj-WhiteLEDDrvr.html
> > As most of these are very simple, I have simulated
> > a number of them with SPICE, but none of them
> > produce the advertised results. What is the mystery ?
> > Some even have supposed oscilloscope traces !! Any
> > thoughts hints would be helpful. Thanks in advance.
>    Dear electronic idiot: learn to read and understand a schematic!
>    If you claim that your SPICE "simulation" did not work,then that 
> indicates your ignorance in electronics.

Dear electronic genius, pray pass on some
of your deep and profound knowledge in the subject, so that guys like me can read and understand schematics correctly.

On Thursday, November 13, 2014 7:02:01 AM UTC-5, Ian Malcolm wrote:
> dakupoto@gmail.com wrote in
> news:74eddd6b-53e9-4bac-b29d-5cc40e3544a1@googlegroups.com: 
> 
> > Could some electronics guru please shed some light 
> > on this ? Several Web sites(please check list below)
> > have schematics and flashy color photographs of 
> > single white led light powered off a single 1.5 Volt 
> > AA battery.
> > http://cappels.org/dproj/ledpage/leddrv.htm
> > http://www.electroschematics.com/6195/high-efficiency-led-with-1-5-volt
> > s/ 
> > dinspirations.com/appliedcontent/Projects/Proj-WhiteLEDDrvr/Proj-WhiteL
> > EDDrvr.html As most of these are very simple, I have simulated 
> > a number of them with SPICE, but none of them 
> > produce the advertised results. What is the mystery ?
> > Some even have supposed oscilloscope traces !! Any 
> > thoughts hints would be helpful. Thanks in advance.
> 
> This class of single transistor blocking oscillator boost converter 
> designed to drive a LED from a single cell is colloquially known as a 
> "Joule Thief".   Searching for that term with the keywords 'SPICE 
> simulation' will find many simulations of varying degrees of accuracy.  
> The basic circuit is pretty forgiving, and can easily be got working with 
> junk-box parts which accounts for its popularity.
> 
> If the simulation doesn't model non-ideal behaviour of key components to 
> a reasonable level of accuracy, it will *NOT* produce realistic results.
> Have you accounted for the cell's internal resistance, the resistance of 
> the transformer primary, transformer core saturation, the LED's junction 
> capacitance and the transistor's gain falling at high collector currents?
> 
> Post your simulations (preferably in LTSPICE format) and the observed 
> results you are trying to match up with and chances are, someone will 
> point out what you've missed.
> 
> -- 
> Ian Malcolm.   London, ENGLAND.  (NEWSGROUP REPLY PREFERRED) 
> ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk 
> [at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL

Yes, I agree totally that unless the non-linearities in the key inductor 
behavior are modeled correctly, the 
SPICE simulation would work. As for 
the transistor, I have used the standard
SPICE model for 2N4401. The diode 
has not yet been inserted. I was just
trying to see if the oscillations could 
be simulated first. Unfortunately, I 
use HSpice at work, and Ngspice at 
home(the simulations were done in my
spare time), both of which use text
based source files as input, as opposed
to LTSpice's GUI based format.

On Friday, 14 November 2014 09:48:48 UTC+11, Robert Baer  wrote:
> Bill Sloman wrote:
> > On Thursday, 13 November 2014 14:18:47 UTC+11, daku...@gmail.com  wrote:
> >> Could some electronics guru please shed some light
> >> on this ? Several Web sites(please check list below)
> >> have schematics and flashy color photographs of
> >> single white led light powered off a single 1.5 Volt
> >> AA battery.
> >> http://cappels.org/dproj/ledpage/leddrv.htm
> >> http://www.electroschematics.com/6195/high-efficiency-led-with-1-5-volts/
> >
> > <snipped - didn't work, with error 404>
> * Both references worked for me.

There were three url's in the original post - I'd snipped the one that didn't work, and marked the snip.

<snipped the rest>

-- 
Bill Sloman, Sydney

Bill Sloman wrote:
> On Thursday, 13 November 2014 14:18:47 UTC+11, daku...@gmail.com  wrote:
>> Could some electronics guru please shed some light
>> on this ? Several Web sites(please check list below)
>> have schematics and flashy color photographs of
>> single white led light powered off a single 1.5 Volt
>> AA battery.
>> http://cappels.org/dproj/ledpage/leddrv.htm
>> http://www.electroschematics.com/6195/high-efficiency-led-with-1-5-volts/
>
> <snipped - didn't work, with error 404>
* Both references worked for me.
   Both show a complete schematic that works.
   You seem to be communicating with an electronic idiot.

>
>> As most of these are very simple, I have simulated
>> a number of them with SPICE, but none of them
>> produce the advertised results. What is the mystery ?
>> Some even have supposed oscilloscope traces !! Any
>> thoughts hints would be helpful. Thanks in advance.
>
> The "mystery" is that a white-light LED is actually a blue-emitting LED exciting a broad-band - white light - phosphor, and blue-emitting LED's need more than 1.5V of drive.
>
> http://en.wikipedia.org/wiki/Light-emitting_diode
>
> suggests that blue-emitting LEDs need between 2.48 and 3.7V of forward voltage to push any electrons through the junction.
>
> In order to get this kind of voltage out of a 1.5V battery, you need some kind of switched-mode power supply, as described in the first two urls you posted.
>
> Neither description is a particularly detailed. There are a lot of different ways to use an inductor and some kind of fast switch to turn current drawn from a 1.5V dry cell into a rather smaller current at a high enough voltage to drive a blue LED. The better ones can convert more than 90% of the energy drawn from the battery into current flowing through the LED.
>
> Which one you'd choose in any particular situation depends on what kind of inductor you could get your hands on. When I've had access to coil-winding machines I've wound my own transformers ....
>

dakupoto@gmail.com wrote:
> Could some electronics guru please shed some light
> on this ? Several Web sites(please check list below)
> have schematics and flashy color photographs of
> single white led light powered off a single 1.5 Volt
> AA battery.
> http://cappels.org/dproj/ledpage/leddrv.htm
> http://www.electroschematics.com/6195/high-efficiency-led-with-1-5-volts/
> dinspirations.com/appliedcontent/Projects/Proj-WhiteLEDDrvr/Proj-WhiteLEDDrvr.html
> As most of these are very simple, I have simulated
> a number of them with SPICE, but none of them
> produce the advertised results. What is the mystery ?
> Some even have supposed oscilloscope traces !! Any
> thoughts hints would be helpful. Thanks in advance.
   Dear electronic idiot: learn to read and understand a schematic!
   If you claim that your SPICE "simulation" did not work,then that 
indicates your ignorance in electronics.