> On 3/17/2012 2:02 PM, Robert Baer wrote:
>> P E Schoen wrote:
>>> "David White" wrote in message news:4f627fb8.3433125@news.tpg.com.au...
>>>
>>>
>>>> I am trying an experiment using the circuit below to power a 3V LCD
>>>> digital clock.
>>>
>>>> http://www.4shared.com/photo/WdTFliAW/Ambient-power.html
>>>
>>> [snip]
>>>
>>> C1 is shown backwards. And you might get better results with Schottky
>>> diodes, although leakage may be more of a problem than forward drop.
>>>
>>> A better antenna might be some chicken wire stretched along some
>>> insulated posts, or maybe a frame made of PVC pipe.
>>>
>>> Paul
>> Capacitor polarity is not significant at the low voltages present.
>
> Interesting, I guess I don't understand how polarized caps
> work...assuming electrolytic.
> Why won't 1.5V reverse degrade the cap?
> How High can I go in reverse without damage?
* Depends on the brand and series. The Sprague TE series, at least 30-40
years ago, worked very well with little degradation from 1/2 to 3/4 of
rating in reverse direction.
So well, that i never bought an unpolarized electrolytic because a TE
near double required rating was a lot less expensive.
>
>> Leakage in Schottky or flower power diodes (VERY similar) for all
>> practical purposes is not significant even for DC frequencies like those
>> in the broadcast band.
>>
>
Reply by mike●March 17, 20122012-03-17
On 3/17/2012 2:02 PM, Robert Baer wrote:
> P E Schoen wrote:
>> "David White" wrote in message news:4f627fb8.3433125@news.tpg.com.au...
>>
>>
>>> I am trying an experiment using the circuit below to power a 3V LCD
>>> digital clock.
>>
>>> http://www.4shared.com/photo/WdTFliAW/Ambient-power.html
>>
>> [snip]
>>
>> C1 is shown backwards. And you might get better results with Schottky
>> diodes, although leakage may be more of a problem than forward drop.
>>
>> A better antenna might be some chicken wire stretched along some
>> insulated posts, or maybe a frame made of PVC pipe.
>>
>> Paul
> Capacitor polarity is not significant at the low voltages present.
Interesting, I guess I don't understand how polarized caps
work...assuming electrolytic.
Why won't 1.5V reverse degrade the cap?
How High can I go in reverse without damage?
> Leakage in Schottky or flower power diodes (VERY similar) for all
> practical purposes is not significant even for DC frequencies like those
> in the broadcast band.
>
Reply by mike●March 17, 20122012-03-17
On 3/17/2012 2:10 PM, Robert Baer wrote:
> mike wrote:
>> On 3/17/2012 12:36 AM, P E Schoen wrote:
>>> "David White" wrote in message news:4f627fb8.3433125@news.tpg.com.au...
>>>
>>>
>>>> I am trying an experiment using the circuit below to power a 3V LCD
>>>> digital clock.
>>>
>>>>
>>>
>>> [snip]
>>>
>>> C1 is shown backwards. And you might get better results with Schottky
>>> diodes, although leakage may be more of a problem than forward drop.
>>
>> I just stuck a 1N21WE on the curve tracer.
>> Forward voltage is less than a tenth of a volt at currents required to
>> run a clock.
>> Reverse leakage is 10uA at 1.5V. AT 65F. So, if you don't get 'em hot
>> they might be a net win over the silicon diodes. Maybe use pairs in
>> series. NO idea what they cost these days.
> * One look at the designation and i instantly (100mSec?) thought "that
> has gotta be a point contact microwave diode".
> So i got curious and used the Baby Gull (google) and first hit was "Buy
> 1N21WE - In Stock & on sale for $74.64".
WOW!!!!
I've got 65 of 'em still in their little lead cocoons.
I was gonna buy some gold, but it looks like my future is secure
with my investment in diodes.
I tried to calculate the ROI on an investment in 4 of 'em as an energy
harvester.
At 10-cents/kWH my calculator didn't have enough zeros to show the
result.
A potato battery would be more efficient.
And you can eat the potato...
Composting toilet...
Grow more potatoes...
Circle of life.
Now, that's green...or at least brown...
> Wow! on "sale" at seventy five smackeroos?
> How much then would the regular price be?...
>
>>>
>>> A better antenna might be some chicken wire stretched along some
>>> insulated posts, or maybe a frame made of PVC pipe.
> * With or without the chickens?
>
>>>
>>> Paul
>>
>
Reply by Robert Baer●March 17, 20122012-03-17
P E Schoen wrote:
> "David White" wrote in message news:4f627fb8.3433125@news.tpg.com.au...
>
>
>> I am trying an experiment using the circuit below to power a 3V LCD
>> digital clock.
>
>> http://www.4shared.com/photo/WdTFliAW/Ambient-power.html
>
> [snip]
>
> C1 is shown backwards. And you might get better results with Schottky
> diodes, although leakage may be more of a problem than forward drop.
>
> A better antenna might be some chicken wire stretched along some
> insulated posts, or maybe a frame made of PVC pipe.
>
> Paul
Capacitor polarity is not significant at the low voltages present.
Leakage in Schottky or flower power diodes (VERY similar) for all
practical purposes is not significant even for DC frequencies like those
in the broadcast band.
Reply by Robert Baer●March 17, 20122012-03-17
mike wrote:
> On 3/17/2012 12:36 AM, P E Schoen wrote:
>> "David White" wrote in message news:4f627fb8.3433125@news.tpg.com.au...
>>
>>
>>> I am trying an experiment using the circuit below to power a 3V LCD
>>> digital clock.
>>
>>> http://www.4shared.com/photo/WdTFliAW/Ambient-power.html
>>
>> [snip]
>>
>> C1 is shown backwards. And you might get better results with Schottky
>> diodes, although leakage may be more of a problem than forward drop.
>
> I just stuck a 1N21WE on the curve tracer.
> Forward voltage is less than a tenth of a volt at currents required to
> run a clock.
> Reverse leakage is 10uA at 1.5V. AT 65F. So, if you don't get 'em hot
> they might be a net win over the silicon diodes. Maybe use pairs in
> series. NO idea what they cost these days.
* One look at the designation and i instantly (100mSec?) thought "that
has gotta be a point contact microwave diode".
So i got curious and used the Baby Gull (google) and first hit was
"Buy 1N21WE - In Stock & on sale for $74.64".
Wow! on "sale" at seventy five smackeroos?
How much then would the regular price be?...
>>
>> A better antenna might be some chicken wire stretched along some
>> insulated posts, or maybe a frame made of PVC pipe.
* With or without the chickens?
>>
>> Paul
>
Reply by mike●March 17, 20122012-03-17
On 3/17/2012 12:36 AM, P E Schoen wrote:
> "David White" wrote in message news:4f627fb8.3433125@news.tpg.com.au...
>
>
>> I am trying an experiment using the circuit below to power a 3V LCD
>> digital clock.
>
>> http://www.4shared.com/photo/WdTFliAW/Ambient-power.html
>
> [snip]
>
> C1 is shown backwards. And you might get better results with Schottky
> diodes, although leakage may be more of a problem than forward drop.
I just stuck a 1N21WE on the curve tracer.
Forward voltage is less than a tenth of a volt at currents required to
run a clock.
Reverse leakage is 10uA at 1.5V. AT 65F. So, if you don't get 'em hot
they might be a net win over the silicon diodes. Maybe use pairs in
series. NO idea what they cost these days.
>
> A better antenna might be some chicken wire stretched along some
> insulated posts, or maybe a frame made of PVC pipe.
>
> Paul
Reply by mike●March 17, 20122012-03-17
On 3/17/2012 12:36 AM, P E Schoen wrote:
> "David White" wrote in message news:4f627fb8.3433125@news.tpg.com.au...
>
>
>> I am trying an experiment using the circuit below to power a 3V LCD
>> digital clock.
>
>> http://www.4shared.com/photo/WdTFliAW/Ambient-power.html
>
> [snip]
>
> C1 is shown backwards. And you might get better results with Schottky
> diodes, although leakage may be more of a problem than forward drop.
>
> A better antenna might be some chicken wire stretched along some
> insulated posts, or maybe a frame made of PVC pipe.
>
> Paul
There are always exceptions, but most of us would get better results
with a MUCH higher frequency receiver.
Local dollar store sells solar yard lamps with the receiver with small
built-in antenna (AKA solar cell)
rechargeable battery and boost converter that can do 3V....all for a buck.
Light is about as ambient as it gets.
Reply by P E Schoen●March 17, 20122012-03-17
"David White" wrote in message news:4f627fb8.3433125@news.tpg.com.au...
> I am trying an experiment using the circuit below to power a 3V LCD
> digital clock.
[snip]
C1 is shown backwards. And you might get better results with Schottky=20
diodes, although leakage may be more of a problem than forward drop.
A better antenna might be some chicken wire stretched along some =
insulated=20
posts, or maybe a frame made of PVC pipe.
Paul=20
Reply by Robert Baer●March 17, 20122012-03-17
David White wrote:
> I am trying an experiment using the circuit below to power a 3V LCD
> digital clock.
>
> http://www.4shared.com/photo/WdTFliAW/Ambient-power.html
>
> The antenna is connected to one of the purlins of my metal garage. The
> ground is connected to the 110V wall socket ground pin.
>
> However, the caps charge up MUCH better when I simply hold the ground
> wire from the module in my hand, eg. 3 or 4VDC this way as opposed to
> less than half a volt.
>
> Is there a reason for this? Is my wall socket ground defective?
>
> David White
>
>
You are tossing a large amount of the signal by using sand power
instead of flower power.
Reply by miso●March 15, 20122012-03-15
On 3/15/2012 4:54 PM, David White wrote:
> I am trying an experiment using the circuit below to power a 3V LCD
> digital clock.
>
> http://www.4shared.com/photo/WdTFliAW/Ambient-power.html
>
> The antenna is connected to one of the purlins of my metal garage. The
> ground is connected to the 110V wall socket ground pin.
>
> However, the caps charge up MUCH better when I simply hold the ground
> wire from the module in my hand, eg. 3 or 4VDC this way as opposed to
> less than half a volt.
>
> Is there a reason for this? Is my wall socket ground defective?
>
> David White
>
>
Your body is a capacitor with a parallel resistor. In ESD testing, that
is 100pf and 1500 ohms as a standard. Now in real life, I could believe
100pf. Probably your resistance to ground is higher than 1500 ohm. So
you are breaking the direct leakage path which I assume exists between
the metal shelter and ground. But going through your body, I doubt you
can get much current. You get 3V, but this is more likely a function of
the meter you are using being high impedance.
I would venture a guess hat the rain gutter on the house is a better
source of an antenna, presuming it doesn't touch the ground. Lots of
metal, high in the air, sounds about as good as it can get.
Have you considered a crystal radio?