Simple useful appliance?

On 02/07/2018 01:50 PM, Rob wrote:
> Jeff Liebermann <jeffl@cruzio.com> wrote:
>> Developing world?  A fairly high percentage of people in Africa have
>> cell phones or smartphones (to discourage POTS line copper theft):
> 
> Over here, making such a statement would result in you being called
> a RACIST and being trending on Twitter all day.
> 

An unqualified statement "Africans tend to steal stuff" probably would. 
That isn't what he said

On 02/07/2018 08:03 AM, tabbypurr@gmail.com wrote:
> George said he needed a problem to think about.... here's a bit of a change from your usual design projects.
> 
> What's the simplest useful electronic product you can think of? Excluded are small amplifiers & oscillators, those have been done. Heating items such as kettles are excluded as they won't be very useful in this situation. Reaction radios are out due to legal issues.
> 
> By useful I mean in areas of the developing world where electricity is available to a percentage of users. The item must be makeable entirely from parts from scrap, your digikey budget is zero. So no uncommon components.
> 
> It could be a domestic item, business item, manufacturing tool, anything of use.
> 
> 
> NT
> 

9 volt battery + steel wool to start a fire

On 02/07/2018 08:03 AM, tabbypurr@gmail.com wrote:
> George said he needed a problem to think about.... here's a bit of a change from your usual design projects.
> 
> What's the simplest useful electronic product you can think of? Excluded are small amplifiers & oscillators, those have been done. Heating items such as kettles are excluded as they won't be very useful in this situation. Reaction radios are out due to legal issues.
> 
> By useful I mean in areas of the developing world where electricity is available to a percentage of users. The item must be makeable entirely from parts from scrap, your digikey budget is zero. So no uncommon components.
> 
> It could be a domestic item, business item, manufacturing tool, anything of use.
> 
> 
> NT
> 

The 555 timer rain alarm is a classic that's pretty useful in areas of 
the world that get unpredictable, sudden torrential downpours:

<https://electrosome.com/wp-content/uploads/2016/06/Rain-Alarm-using-555-Timer-PCB-1.jpg>

On Wed, 7 Feb 2018 20:00:10 +0000 (UTC), Long Hair
<DecadentLinuxUserNumeroUno@decadentlinuxuser.org> wrote:

>The absolute best way is to have a nice say 22kW Generac backup
>generator AND a good power conditioner on your system.

I hope you don't mean a ferroresonant transformer as a "power
conditioner".  They work nicely, as long as you feed it with 60 Hz.
Low in frequency, and the output voltage drops.  High in frequency,
and it climbs.  Details:
<http://www.powerqualityworld.com/2011/04/constant-voltage-ferroresonant.html>
Also, they're not very efficient (about 75%), get rather warm, and
buzz loudly.  Despite these disadvantages, I've used them effectively
with computers in place of a UPS.  I was doing some programming during
a lightning storm.  The overhead fluorescent lights were flashing
intermittently as the power flickered on and off, but the computah
never missed a beat.  

Most generators do not produce a clean sine wave or deliver a constant
60.0 Hz.  The result is an even worse looking waveform from the
ferroresonant xformer, wide voltage variations, or both.  Therefore, I
would recommend *EITHER* a generator or a ferroresonant power
conditioner, but not both.

>Then, you simply go to sleep without a worry about what happens or
>happened to your power that night.

What, me worry?  Most of my critical gizmos are DC charged or
operated.  I went through considerable difficulty finding phones,
answering machinery, modems, routers, switches, media players, TV,
hi-fi, etc, that run on 10-14VDC (also known as 12VDC nominal).  These
are run by several big lead-acid or gel cell batteries, and charged by
either a marine battery charger during the winter, or a solar panel
during the summer.  If the power goes out at night, I usually don't
notice.

>Put some of your lights, your heating and air system, your kitchen,
>and your computer UPSs on it.  

The desktop computahs and one big monitor are the only devices with
UPS protection because my battery system simply doesn't have the
capacity to run them.  Also, finding desktops that run on 12VDC is
rather difficult.  The plan is to switch to lower power desktop
computers (laptop in a box) which will run on battery power, and
dispose of the UPS.  

>Your neighbors will always say "he's the
>only one on the street who's lights never go out.

That's been a problem.  We had a storm a few years ago that dropped
quite a few trees in the area.  The power utility (PG&E) ran around
fixing downed power lines.  Mine was one of the last to get fixed
because the lineman saw that my house was normally lighted and drove
by thinking that I had working utility power.  I switched to kerosene
and propane lamps for emergency lighting and have not had that problem
again.

-- 
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

On 02/07/2018 12:43 PM, tabbypurr@gmail.com wrote:
> On Wednesday, 7 February 2018 19:07:56 UTC, Bill Martin  wrote:
>> On 02/07/2018 10:09 AM, Jeff Liebermann wrote:
>>> On Wed, 7 Feb 2018 05:03:57 -0800 (PST), tabbypurr wrote:
>>>
>>>> By useful I mean in areas of the developing world where electricity
>>>> is available to a percentage of users.
>>>
>>> Or, a percentage of time.  I'm told that power in the developing world
>>> is often intermittent and unreliable.  I have that problem living in
>>> the forest, where the power wires are known to attract falling trees.
>>> Damage to electronics from voltage surges usually occurs when the
>>> power is restored, so I unplug or turn off (at the breaker panel)
>>> power to any sensitive devices.  The problem is that in the middle of
>>> the night, there's no easy way for me to determine that the power had
>>> been restored.  So, I built a "Power Restoration Wake Up Alarm" that
>>> makes loud buzzing noises when power comes back.  This might be a bit
>>> too complicated for the proposed design project.  Instead, I suggest
>>> inserting a small power diode (1N4002) into the wall outlet.  When the
>>> power returns, the diode explodes, making enough noise to alert or
>>> wake the residents.  It can't get much simpler than a single diode.
>>>
>> How about an ac relay, normally open type, in the power line input to
>> the gadget you want to protect, with the coil powered from the "on"
>> contact side. Power drops out, relay disconnects from power line, power
>> comes back but will not energize the relay until you manually reset it,
>> by pushing the contactor down by hand. Use a stick to push it!
> 
> I'm not clear what appliances would be protected from what
> 
> 
> NT
> 
you miss the power surge when it is restored...

On Wed, 7 Feb 2018 11:07:50 -0800, Bill Martin <wwm@wwmartin.net>
wrote:

>On 02/07/2018 10:09 AM, Jeff Liebermann wrote:
>> On Wed, 7 Feb 2018 05:03:57 -0800 (PST), tabbypurr@gmail.com wrote:
>> 
>>> By useful I mean in areas of the developing world where electricity
>>> is available to a percentage of users.
>> 
>> Or, a percentage of time.  I'm told that power in the developing world
>> is often intermittent and unreliable.  I have that problem living in
>> the forest, where the power wires are known to attract falling trees.
>> Damage to electronics from voltage surges usually occurs when the
>> power is restored, so I unplug or turn off (at the breaker panel)
>> power to any sensitive devices.  The problem is that in the middle of
>> the night, there's no easy way for me to determine that the power had
>> been restored.  So, I built a "Power Restoration Wake Up Alarm" that
>> makes loud buzzing noises when power comes back.  This might be a bit
>> too complicated for the proposed design project.  Instead, I suggest
>> inserting a small power diode (1N4002) into the wall outlet.  When the
>> power returns, the diode explodes, making enough noise to alert or
>> wake the residents.  It can't get much simpler than a single diode.
 
>How about an ac relay, normally open type, in the power line input to 
>the gadget you want to protect, with the coil powered from the "on" 
>contact side. Power drops out, relay disconnects from power line, power 
>comes back but will not energize the relay until you manually reset it, 
>by pushing the contactor down by hand. Use a stick to push it!

I can sorta see how that might be useful.  However, you have not met
the original design requirements, which I understand to be:
1.  Keep George Herold busy and out of trouble.
2.  Design the "simplest useful electronic product".  I'm assuming
that means minimum components count.
3.  Operate in an area where power is only available to a "percentage"
of users.  I interpret this to mean unreliable power or no power at
all.
4.  "Must be makeable entirely from parts from scrap" which eliminates
any purchased, custom, new, exotic, sophisticated, or expensive
components.  In other words, made for eWaste.
5.  "Could be a domestic item, business item, manufacturing tool,
anything of use".  

As I see it, your proposed device would not meet any of these design
requirements.  Well, maybe #5, which is inordinately broad.

-- 
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

On 02/07/2018 03:35 PM, Jeff Liebermann wrote:
> On Wed, 7 Feb 2018 11:07:50 -0800, Bill Martin <wwm@wwmartin.net>
> wrote:
> 
>> On 02/07/2018 10:09 AM, Jeff Liebermann wrote:
>>> On Wed, 7 Feb 2018 05:03:57 -0800 (PST), tabbypurr@gmail.com wrote:
>>>
>>>> By useful I mean in areas of the developing world where electricity
>>>> is available to a percentage of users.
>>>
>>> Or, a percentage of time.  I'm told that power in the developing world
>>> is often intermittent and unreliable.  I have that problem living in
>>> the forest, where the power wires are known to attract falling trees.
>>> Damage to electronics from voltage surges usually occurs when the
>>> power is restored, so I unplug or turn off (at the breaker panel)
>>> power to any sensitive devices.  The problem is that in the middle of
>>> the night, there's no easy way for me to determine that the power had
>>> been restored.  So, I built a "Power Restoration Wake Up Alarm" that
>>> makes loud buzzing noises when power comes back.  This might be a bit
>>> too complicated for the proposed design project.  Instead, I suggest
>>> inserting a small power diode (1N4002) into the wall outlet.  When the
>>> power returns, the diode explodes, making enough noise to alert or
>>> wake the residents.  It can't get much simpler than a single diode.
>   
>> How about an ac relay, normally open type, in the power line input to
>> the gadget you want to protect, with the coil powered from the "on"
>> contact side. Power drops out, relay disconnects from power line, power
>> comes back but will not energize the relay until you manually reset it,
>> by pushing the contactor down by hand. Use a stick to push it!
> 
> I can sorta see how that might be useful.  However, you have not met
> the original design requirements, which I understand to be:
> 1.  Keep George Herold busy and out of trouble.
	well, I can't help there :-)
> 2.  Design the "simplest useful electronic product".  I'm assuming
> that means minimum components count.
	One part...not minimal enough?
> 3.  Operate in an area where power is only available to a "percentage"
> of users.  I interpret this to mean unreliable power or no power at
> all.
	Well, no power at all, who cares..nothing is going to work anyway. This 
might help with the intermittent case.
> 4.  "Must be makeable entirely from parts from scrap" which eliminates
> any purchased, custom, new, exotic, sophisticated, or expensive
> components.  In other words, made for eWaste.
	There must be some discarded household thing with a big relay in 
it...washing machine maybe?
> 5.  "Could be a domestic item, business item, manufacturing tool,
> anything of use".
> 
> As I see it, your proposed device would not meet any of these design
> requirements.  Well, maybe #5, which is inordinately broad.
	Oh well, I'm not forcing anybody to build it!

> 

On Wed, 7 Feb 2018 11:21:23 -0800 (PST), tabbypurr@gmail.com wrote:

>On Wednesday, 7 February 2018 17:00:17 UTC, Carl Ijames  wrote:
>> What do you mean by a "reaction" radio?

>positive feedback on the rf circuit - good sensitity, goodish 
>selectivity with minimal parts count. The downside is the risk
>of oscillation and unintended broadcast of this interference, 
>so they're no go.
>NT

Do you mean super regenerative receivers?
Most of the common 315/433MHz radio links have super regenerative
receivers:
<https://www.alibaba.com/showroom/433mhz-superregeneration-wireless-receiver-module.html>
<https://www.google.com/patents/US20020168957>

-- 
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

On Wednesday, 7 February 2018 23:18:42 UTC, Jeff Liebermann  wrote:


> capacity to run them.  Also, finding desktops that run on 12VDC is
> rather difficult. 

Can you not get SM convertors for the various rails from ebay etc?


> by thinking that I had working utility power.  I switched to kerosene
> and propane lamps for emergency lighting and have not had that problem
> again.

those are way more reliable than electric light IME. Cheap too.


NT

On Wednesday, 7 February 2018 23:15:55 UTC, bitrex  wrote:
> On 02/07/2018 08:03 AM, tabbypurr wrote:

> > George said he needed a problem to think about.... here's a bit of a change from your usual design projects.
> > 
> > What's the simplest useful electronic product you can think of? Excluded are small amplifiers & oscillators, those have been done. Heating items such as kettles are excluded as they won't be very useful in this situation. Reaction radios are out due to legal issues.
> > 
> > By useful I mean in areas of the developing world where electricity is available to a percentage of users. The item must be makeable entirely from parts from scrap, your digikey budget is zero. So no uncommon components.
> > 
> > It could be a domestic item, business item, manufacturing tool, anything of use.
> > 
> > 
> > NT
> > 
> 
> The 555 timer rain alarm is a classic that's pretty useful in areas of 
> the world that get unpredictable, sudden torrential downpours:
> 
> <https://electrosome.com/wp-content/uploads/2016/06/Rain-Alarm-using-555-Timer-PCB-1.jpg>

Could you explain how it would be useful?


NT