On 4/14/2021 6:26 PM, Steve Wilson wrote:
> Steve Wilson <spam@me.com> wrote:
> 
> Second problem: I do not need to download a program to simply upload a
> small zip once in a while. I do not need the hassle of learning another
> program with all its hooks and traps. I do not want a program that has the
> capability of uploading all my files if it is not configured properly.
> This has the potential of uploading garbage if a file is corrupted, which
> would destroy my backups.
> 
> I don't want a program that can destroy itself if an update is corrupted.
> Microsoft is the perfect example of what can happen with automatic updates
> that destroy files or shut your system down, and Dropbox has incorporated
> unpopular changes without recourse. I have other more secure ways of
> handling backups and I don't want a Dropbox style program in my system.
> 
> Other file upload programs I have tried have onerous conditions, such as
> erasing your files after a week or a month, or erasing them after a period
> of inactivity. I need something that will be permanent and operate with
> minimum hassle.
> 
> Even with the file sharing glitch, Google Drive appears to be the best
> available option. If there are other file sharing programs I am not aware
> of, please let me know.

There are advantages to having files "disappear" after a while.
I rarely want to leave something available (on a server that I
don't control) for very long.

I've used Mediafire intermittently, in the past.  But, it has
a 10G limit on free accounts (which is fine for me as I only
push things to that site when I don't want folks accessing my
server).  As it is entirely web-based, there's no software to
install on your computer (besides a browser).

And, YOU have to explicitly "upload" content so no fear of "it"
deciding to harvest stuff from your machine.

I've played with Mega NZ in the past.  I'm not sure if you can
use it without their "helper app" (it's been a while)

[I'm not a fan of google.]

Steve Wilson <spam@me.com> wrote:

[...]
 
> I will have to figure out how to share google drive links without going 
> through all this mess. But all the other file sharing sites have croaked
> or have much worse login problems. I will have to see if I can get
> Dropbox to work, but I definitely do not want it uploading all my other
> files to the cloud. Hopefully I can find a solution that everyone else
> can use. This would make it easier to upload LTspice files without
> having to post the ASC and PLT files to the newsgroup. That is such a
> pain, especially when you have to deal with line wrap problems caused by
> news clients.) 

I tried to install the free version of Dropbox:

https://www.dropbox.com/install

It gave the following messages:

Get started by downloading Dropbox on your computer.
Set up Dropbox
Update your computer
To run the Dropbox desktop application, you&#4294967295;ll need Windows 7 or higher.
 
First problem: I am currently running Win XP.

Second problem: I do not need to download a program to simply upload a 
small zip once in a while. I do not need the hassle of learning another 
program with all its hooks and traps. I do not want a program that has the 
capability of uploading all my files if it is not configured properly. 
This has the potential of uploading garbage if a file is corrupted, which 
would destroy my backups. 

I don't want a program that can destroy itself if an update is corrupted. 
Microsoft is the perfect example of what can happen with automatic updates 
that destroy files or shut your system down, and Dropbox has incorporated 
unpopular changes without recourse. I have other more secure ways of 
handling backups and I don't want a Dropbox style program in my system.

Two other file programs that used to work are now broken or have gone 
intermittent:

Sabercat:
https://sabercathost.com/

TinyUpload:
http://tinyupload.com/index.php

Other file upload programs I have tried have onerous conditions, such as 
erasing your files after a week or a month, or erasing them after a period 
of inactivity. I need something that will be permanent and operate with 
minimum hassle.

Even with the file sharing glitch, Google Drive appears to be the best 
available option. If there are other file sharing programs I am not aware 
of, please let me know.




-- 
The best designs occur in the theta state. - sw

Piglet <erichpwagner@hotmail.com> wrote:

> On 13/04/2021 13:18, Steve Wilson wrote:
[...]

>>>> Nice. Here it is in LTspice:
>>>>
>>>> https://tinyurl.com/hazvjhfk
>>>>
>>>>
>>>>
>>> Thanks Steve, that gets me to a google drive link that wants a login?
>>>
>>> That two transistor complementary oscillator has a 1960s feel to it
>>> but works well in low power applications like this because most of the
>>> time both devices are non-conducting.
>>>
>>> piglet
>>
>> Thanks. I thought I had enabled sharing, but there is a separate
>> procedure to follow that is new.
>>
>> I checked the file. It should work now. Ignore the signin link in the
>> upper right.
>>
>> Let me know if you find any more problems.
>>
> 
> Thanks Steve, that simulates nicely.
> 
> piglet
 
Thanks piglet. Very nice circuit. I like the multivibrator and current 
limiting driver. Very simple and very elegant. I will save your circuit for 
future reference. 

(BTW, I had to sign out of google to test the link. Now google wants me to 
sign in with my password every time I log in. I fixed it by saving the 
cookie after signing in. Now google stops complaining. I did the same with 
eBay and it also stopped complaining. I reload the cookies every time I 
reboot, so the file doesn't get clogged with cookies from other sites.

I will have to figure out how to share google drive links without going 
through all this mess. But all the other file sharing sites have croaked or 
have much worse login problems. I will have to see if I can get Dropbox to 
work, but I definitely do not want it uploading all my other files to the 
cloud. Hopefully I can find a solution that everyone else can use. This 
would make it easier to upload LTspice files without having to post the ASC 
and PLT files to the newsgroup. That is such a pain, especially when you 
have to deal with line wrap problems caused by news clients.)



-- 
The best designs occur in the theta state. - sw

On 13/04/2021 13:18, Steve Wilson wrote:
> piglet <erichpwagner@hotmail.com> wrote:
>
>> On 13/04/2021 4:24 am, Steve Wilson wrote:
>>> piglet <erichpwagner@hotmail.com> wrote:
>>>
>>>> On 12/04/2021 12:09 pm, rhor...@gmail.com wrote:
>>>>> On Sunday, April 11, 2021 at 4:53:49 AM UTC-5, piglet wrote:
>>>>>
>>>>>> I thought the OP was trying to flash a LED at low duty cycle?
>>>>> That is correct.  This circuit is designed to turn the flashlight on
>>>>> when a reflective target is placed in front of a TCRT5000L
>>>>> retroreflector and off when a non-reflective target is placed in
>>>>> front of the TCRT5000L.  The intent is for the battery to last at
>>>>> least 6 months with an acceptably low amount of battery drain (less
>>>>> than 20% of full charge).  This means the entire circuit must draw
>>>>> significantly less than 1 mA when off.  In order to manage this, I
>>>>> employ a series of 7 pulses  over a period of about 2ms to trigger
>>>>> the unit to switch on when the reflective target is in place.  These
>>>>> pulses are created by a TLC555.  The reset pin is driven  by a pulse
>>>>> created by a very low duty cycle circuit which draws only a fraction
>>>>> of a uV and produces a 2ms pulse every few hundred ms.  The circuit
>>>>> draws an average of about 85 uA, including the high current (~100 mA)
>>>>> pulses.
>>>>>
>>>>>> might do that with 4-5 descrete transistors for less than the cost
>>>>>> of a micropower comparator but the OP presumably has his reasons.
>>>>>
>>>>> If you can drive the TCRT500L near its maximum of 60 mA instantaneous
>>>>> current while still drawing significantly less than 200uA average
>>>>> using a few discrete transistors, I am all ears.  I am using a 3.3V
>>>>> power supply in order to minimize the current, but 5V at about half
>>>>> the current would also be fine.
>>>>>
>>>>
>>>> Ignoring the complication of a burst of 7 pulses here is a first pass
>>>> illustrative sketch. With shown values should give approx 80us pulses
>>>> every 80ms with LED current approx 100mA. Average supply current
>>>> should be a little over 100uA. If you are going to simulate it you may
>>>> need to start the supply from 0V rather than steady-state to help
>>>> simulation astable startup.
>>>>
>>>> <https://www.dropbox.com/s/5yhm1ciy8hvlx6r/SED_LED_Flash.pdf?dl=0>
>>>>
>>>> NPN are gum drop type like 2N3904 and PNP 2N3906 etc etc. Change caps
>>>> to 0.1uF will give approx 40us pulses every 40ms etc.
>>>>
>>>> piglet
>>>
>>> Nice. Here it is in LTspice:
>>>
>>> https://tinyurl.com/hazvjhfk
>>>
>>>
>>>
>> Thanks Steve, that gets me to a google drive link that wants a login?
>>
>> That two transistor complementary oscillator has a 1960s feel to it but
>> works well in low power applications like this because most of the time
>> both devices are non-conducting.
>>
>> piglet
>
> Thanks. I thought I had enabled sharing, but there is a separate procedure
> to follow that is new.
>
> I checked the file. It should work now. Ignore the signin link in the
> upper right.
>
> Let me know if you find any more problems.
>

Thanks Steve, that simulates nicely.

piglet

piglet <erichpwagner@hotmail.com> wrote:

> On 13/04/2021 4:24 am, Steve Wilson wrote:
>> piglet <erichpwagner@hotmail.com> wrote:
>> 
>>> On 12/04/2021 12:09 pm, rhor...@gmail.com wrote:
>>>> On Sunday, April 11, 2021 at 4:53:49 AM UTC-5, piglet wrote:
>>>>
>>>>> I thought the OP was trying to flash a LED at low duty cycle?
>>>> That is correct.  This circuit is designed to turn the flashlight on
>>>> when a reflective target is placed in front of a TCRT5000L
>>>> retroreflector and off when a non-reflective target is placed in
>>>> front of the TCRT5000L.  The intent is for the battery to last at
>>>> least 6 months with an acceptably low amount of battery drain (less
>>>> than 20% of full charge).  This means the entire circuit must draw
>>>> significantly less than 1 mA when off.  In order to manage this, I
>>>> employ a series of 7 pulses  over a period of about 2ms to trigger
>>>> the unit to switch on when the reflective target is in place.  These
>>>> pulses are created by a TLC555.  The reset pin is driven  by a pulse
>>>> created by a very low duty cycle circuit which draws only a fraction
>>>> of a uV and produces a 2ms pulse every few hundred ms.  The circuit
>>>> draws an average of about 85 uA, including the high current (~100 mA)
>>>> pulses. 
>>>>
>>>>> might do that with 4-5 descrete transistors for less than the cost
>>>>> of a micropower comparator but the OP presumably has his reasons. 
>>>>
>>>> If you can drive the TCRT500L near its maximum of 60 mA instantaneous
>>>> current while still drawing significantly less than 200uA average
>>>> using a few discrete transistors, I am all ears.  I am using a 3.3V
>>>> power supply in order to minimize the current, but 5V at about half
>>>> the current would also be fine.
>>>>
>>>
>>> Ignoring the complication of a burst of 7 pulses here is a first pass
>>> illustrative sketch. With shown values should give approx 80us pulses
>>> every 80ms with LED current approx 100mA. Average supply current
>>> should be a little over 100uA. If you are going to simulate it you may
>>> need to start the supply from 0V rather than steady-state to help
>>> simulation astable startup.
>>>
>>> <https://www.dropbox.com/s/5yhm1ciy8hvlx6r/SED_LED_Flash.pdf?dl=0>
>>>
>>> NPN are gum drop type like 2N3904 and PNP 2N3906 etc etc. Change caps
>>> to 0.1uF will give approx 40us pulses every 40ms etc.
>>>
>>> piglet
>> 
>> Nice. Here it is in LTspice:
>> 
>> https://tinyurl.com/hazvjhfk
>> 
>> 
>> 
> Thanks Steve, that gets me to a google drive link that wants a login?
> 
> That two transistor complementary oscillator has a 1960s feel to it but 
> works well in low power applications like this because most of the time 
> both devices are non-conducting.
> 
> piglet

Thanks. I thought I had enabled sharing, but there is a separate procedure
to follow that is new. 

I checked the file. It should work now. Ignore the signin link in the
upper right. 

Let me know if you find any more problems.

-- 
The best designs occur in the theta state. - sw

On 13/04/2021 4:24 am, Steve Wilson wrote:
> piglet <erichpwagner@hotmail.com> wrote:
> 
>> On 12/04/2021 12:09 pm, rhor...@gmail.com wrote:
>>> On Sunday, April 11, 2021 at 4:53:49 AM UTC-5, piglet wrote:
>>>
>>>> I thought the OP was trying to flash a LED at low duty cycle?
>>> That is correct.  This circuit is designed to turn the flashlight on
>>> when a reflective target is placed in front of a TCRT5000L
>>> retroreflector and off when a non-reflective target is placed in front
>>> of the TCRT5000L.  The intent is for the battery to last at least 6
>>> months with an acceptably low amount of battery drain (less than 20% of
>>> full charge).  This means the entire circuit must draw significantly
>>> less than 1 mA when off.  In order to manage this, I employ a series of
>>> 7 pulses  over a period of about 2ms to trigger the unit to switch on
>>> when the reflective target is in place.  These pulses are created by a
>>> TLC555.  The reset pin is driven  by a pulse created by a very low duty
>>> cycle circuit which draws only a fraction of a uV and produces a 2ms
>>> pulse every few hundred ms.  The circuit draws an average of about 85
>>> uA, including the high current (~100 mA) pulses.
>>>
>>>> might do that with 4-5 descrete transistors for less than the cost of
>>>> a micropower comparator but the OP presumably has his reasons.
>>>
>>> If you can drive the TCRT500L near its maximum of 60 mA instantaneous
>>> current while still drawing significantly less than 200uA average using
>>> a few discrete transistors, I am all ears.  I am using a 3.3V power
>>> supply in order to minimize the current, but 5V at about half the
>>> current would also be fine.
>>>
>>
>> Ignoring the complication of a burst of 7 pulses here is a first pass
>> illustrative sketch. With shown values should give approx 80us pulses
>> every 80ms with LED current approx 100mA. Average supply current should
>> be a little over 100uA. If you are going to simulate it you may need to
>> start the supply from 0V rather than steady-state to help simulation
>> astable startup.
>>
>> <https://www.dropbox.com/s/5yhm1ciy8hvlx6r/SED_LED_Flash.pdf?dl=0>
>>
>> NPN are gum drop type like 2N3904 and PNP 2N3906 etc etc. Change caps to
>> 0.1uF will give approx 40us pulses every 40ms etc.
>>
>> piglet
> 
> Nice. Here it is in LTspice:
> 
> https://tinyurl.com/hazvjhfk
> 
> 
> 
Thanks Steve, that gets me to a google drive link that wants a login?

That two transistor complementary oscillator has a 1960s feel to it but 
works well in low power applications like this because most of the time 
both devices are non-conducting.

piglet

piglet <erichpwagner@hotmail.com> wrote:

> On 12/04/2021 12:09 pm, rhor...@gmail.com wrote:
>> On Sunday, April 11, 2021 at 4:53:49 AM UTC-5, piglet wrote:
>> 
>>> I thought the OP was trying to flash a LED at low duty cycle?
>> That is correct.  This circuit is designed to turn the flashlight on
>> when a reflective target is placed in front of a TCRT5000L
>> retroreflector and off when a non-reflective target is placed in front
>> of the TCRT5000L.  The intent is for the battery to last at least 6
>> months with an acceptably low amount of battery drain (less than 20% of
>> full charge).  This means the entire circuit must draw significantly
>> less than 1 mA when off.  In order to manage this, I employ a series of
>> 7 pulses  over a period of about 2ms to trigger the unit to switch on
>> when the reflective target is in place.  These pulses are created by a
>> TLC555.  The reset pin is driven  by a pulse created by a very low duty
>> cycle circuit which draws only a fraction of a uV and produces a 2ms
>> pulse every few hundred ms.  The circuit draws an average of about 85
>> uA, including the high current (~100 mA) pulses. 
>> 
>>> might do that with 4-5 descrete transistors for less than the cost of
>>> a micropower comparator but the OP presumably has his reasons. 
>> 
>> If you can drive the TCRT500L near its maximum of 60 mA instantaneous
>> current while still drawing significantly less than 200uA average using
>> a few discrete transistors, I am all ears.  I am using a 3.3V power
>> supply in order to minimize the current, but 5V at about half the
>> current would also be fine. 
>> 
> 
> Ignoring the complication of a burst of 7 pulses here is a first pass 
> illustrative sketch. With shown values should give approx 80us pulses 
> every 80ms with LED current approx 100mA. Average supply current should 
> be a little over 100uA. If you are going to simulate it you may need to 
> start the supply from 0V rather than steady-state to help simulation 
> astable startup.
> 
> <https://www.dropbox.com/s/5yhm1ciy8hvlx6r/SED_LED_Flash.pdf?dl=0>
> 
> NPN are gum drop type like 2N3904 and PNP 2N3906 etc etc. Change caps to
> 0.1uF will give approx 40us pulses every 40ms etc.
> 
> piglet

Nice. Here it is in LTspice:

https://tinyurl.com/hazvjhfk



-- 
The best designs occur in the theta state. - sw

On Monday, April 12, 2021 at 10:00:44 AM UTC-5, anti...@math.uni.wroc.pl wrote:

> There are a lot of unstated assumptions in what you wrote.
No, there are not.  I did not ask for a circuit design.  I provided that.  All I asked for was either a low cost comparator ( ~ $0.30 or less) that would work with Micro-Cap 12, or for someone to sim the circuit in their own software using an MCP6542.
 >It seems 
> that you want TCRT500L to pulse with about 1/1000 duty cycle at 
Well, 1/1000 would be nice, but the design offers about 0.44%.  Anything under 1/200 should be fine.

> frequency of order 1 Hz.

That's a little too low.  The switch should not take a full second to turn on or off.  On the order of 50 - 100ms is good.
> This is doable using RC oscilator and 
> pulse forming circuit in something like 5-10 transitors. If 
> R are high enough this control circuit will run on few microamps. 
A circuit employing 5 discrete transistors is not too bad.  A circuit with 10 discrete transistors is getting to be a bit of a mess, especially since each component adds to the cost of assembly.  I would absolutely rather have 2 comparators, a 555, and a handful of resistors than two or three dozen discrete components.  There are a number of reasons why manufacturers employ ICs, rather than discrete components, you know.  The design as-is only uses 28 components, mostly resistors.  Unless you can show me differently, I submit any design employing only discrete components is going to have a much higher parts count, and probably be more expensive, provided the MCP6541 or an even less expensive comparator will work.

> But your circuit generates more complicated thing. More 
How is that, again?

> complicated waveforms are easily generated using MCU. AFAICS 
So now you are going from one extreme to the other.  Zero integration to massive integration.  There are plenty of applications where an MCU is all but essential, but this is not one of them, IMO.  If I *WERE* to go that route, I would employ a more complex waveform and decode it on the other side.  The TCRT500L has optical filters that make such complexity unnecessary, or so I hope.

> almost any MCU with low power modes should be able to 
> generate required pulses using less then 10uA of current, 
> some claim below 2uA for such use cases (of course you need to 
At a certain point, reducing the idle current has no significant impact on the average current, since the bulk of the current is delivered during the LED pulses.  Below about 100 uA, the idle current is quite insignificant, and there is no real difference between 2uA and 100uA.

On 12/04/2021 12:09 pm, rhor...@gmail.com wrote:
> On Sunday, April 11, 2021 at 4:53:49 AM UTC-5, piglet wrote:
> 
>> I thought the OP was trying to flash a LED at low duty cycle?
> That is correct.  This circuit is designed to turn the flashlight on when a reflective target is placed in front of a TCRT5000L retroreflector and off when a non-reflective target is placed in front of the TCRT5000L.  The intent is for the battery to last at least 6 months with an acceptably low amount of battery drain (less than 20% of full charge).  This means the entire circuit must draw significantly less than 1 mA when off.  In order to manage this, I employ a series of 7 pulses  over a period of about 2ms to trigger the unit to switch on when the reflective target is in place.  These pulses are created by a TLC555.  The reset pin is driven  by a pulse created by a very low duty cycle circuit which draws only a fraction of a uV and produces a 2ms pulse every few hundred ms.  The circuit draws an average of about 85 uA, including the high current (~100 mA) pulses.
> 
>> might do that with 4-5 descrete transistors for less than the cost of a
>> micropower comparator but the OP presumably has his reasons.
> 
> If you can drive the TCRT500L near its maximum of 60 mA instantaneous current while still drawing significantly less than 200uA average using a few discrete transistors, I am all ears.  I am using a 3.3V power supply in order to minimize the current, but 5V at about half the current would also be fine.
> 

Ignoring the complication of a burst of 7 pulses here is a first pass 
illustrative sketch. With shown values should give approx 80us pulses 
every 80ms with LED current approx 100mA. Average supply current should 
be a little over 100uA. If you are going to simulate it you may need to 
start the supply from 0V rather than steady-state to help simulation 
astable startup.

<https://www.dropbox.com/s/5yhm1ciy8hvlx6r/SED_LED_Flash.pdf?dl=0>

NPN are gum drop type like 2N3904 and PNP 2N3906 etc etc. Change caps to 
0.1uF will give approx 40us pulses every 40ms etc.

piglet

rhor...@gmail.com <rhorerles@gmail.com> wrote:
> On Sunday, April 11, 2021 at 4:53:49 AM UTC-5, piglet wrote:
> 
> > I thought the OP was trying to flash a LED at low duty cycle?
> That is correct.  This circuit is designed to turn the flashlight on when a reflective target is placed in front of a TCRT5000L retroreflector and off when a non-reflective target is placed in front of the TCRT5000L.  The intent is for the battery to last at least 6 months with an acceptably low amount of battery drain (less than 20% of full charge).  This means the entire circuit must draw significantly less than 1 mA when off.  In order to manage this, I employ a series of 7 pulses  over a period of about 2ms to trigger the unit to switch on when the reflective target is in place.  These pulses are created by a TLC555.  The reset pin is driven  by a pulse created by a very low duty cycle circuit which draws only a fraction of a uV and produces a 2ms pulse every few hundred ms.  The circuit draws an average of about 85 uA, including the high current (~100 mA) pulses.
> 
> > might do that with 4-5 descrete transistors for less than the cost of a 
> > micropower comparator but the OP presumably has his reasons. 
> 
> If you can drive the TCRT500L near its maximum of 60 mA instantaneous current while still drawing significantly less than 200uA average using a few discrete transistors, I am all ears.  I am using a 3.3V power supply in order to minimize the current, but 5V at about half the current would also be fine.

There are a lot of unstated assumptions in what you wrote.  It seems
that you want TCRT500L to pulse with about 1/1000 duty cycle at
frequency of order 1 Hz.  This is doable using RC oscilator and
pulse forming circuit in something like 5-10 transitors.  If
R are high enough this control circuit will run on few microamps.
But your circuit generates more complicated thing.  More
complicated waveforms are easily generated using MCU.  AFAICS
almost any MCU with low power modes should be able to
generate required pulses using less then 10uA of current,
some claim below 2uA for such use cases (of course you need to
separately account for TCRT500L current).

-- 
                              Waldek Hebisch