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 >
Ambient Power Module
Started by ●March 15, 2012
Reply by ●March 17, 20122012-03-17
Reply by ●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 ●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 ●March 17, 20122012-03-17
mike wrote:> 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. >> >
