Michel Jullian wrote:
Hi Charlie,
It certainly will if you cool it, otherwise it should radiate exactly
as much energy (blackbody radiation) as it receives, or do I
misunderstand the concept of thermal equilibrium?
As an exercise in seeing whether I understand what Charlie's getting at,
I'll try to answer your question, and we'll see if I'm all wet.
The key here is the reason Charlie's using LEDs, not ordinary diodes.
If you look at the current/voltage curve of an ordinary diode, it's
essentially linear at 0 volts (it's an exponential, but close to zero we
can ignore all but the linear term). This is what the model says;
checking it with an actual diode is a little tricky since the currents
involved are tiny.
The point is there's no sharp cutoff down there -- at ~ 0 volts a diode
conducts about equally well forward or backwards. The "cutoff" comes at
~ 0.6 volts forward bias (for a silicon P/N diode) where dV/dI plunges
rapidly to something close to zero.
A consequence of this is that if you hook a diode, a noisy resistor, and
a capacitor in a loop, the capacitor isn't going to charge -- the
voltage on the diode is going to be very close to zero, and in that
range, the diode just acts like a resistor. In other words, it leaks
like a sieve. No joy there if you want practical free energy.
Charlie's idea is that, if he uses an LED, even though noise on the
resistor may be able to sneak through the diode either way (due to the
low voltage), once in a while a noise pulse will be high enough to kick
a few electrons over the forward barrier voltage, and a light pulse will
come out. The light then leaves the circuit, and its energy can't be
recaptured by the "leaky" diode.
A photocell nearby will catch the light, and turn it back into
electricity. The photocell will be putting out (noisy) DC, not AC, and
can be used to charge a capacitor directly.
So, overall, the idea seems to be to use the LED in order to do an
end-run around the fact that diodes aren't ideal.
I started a series of measurements on diodes at low voltage a long, long
time ago, in a lab course in school (dropped the course, never finished
the measurements). I've been meaning to do that experiment over again a
little differently from the way we were doing it then (use JFETs instead
of a VTVM), and also check one other thing: Can an LED "run backwards"
and operate as a solar cell? I don't know but I suspect the answer is
"yes", which could throw an additional monkey wrench into the works when
trying to use LEDs to cohere noise.
Aloha, Michel
----- Original Message ----- From: "Charles M. Brown"
<[EMAIL PROTECTED]> To: <[email protected]> Sent: Tuesday,
November 13, 2007 9:52 PM Subject: [Vo]:diode array in photodiode
array
Vortexians,
Looking at the array of hexagonal concentrators and spherical photo
diodes in:
photodiodeshttp://www.technologyreview.com/Energy/19696/?nlid=662 I
see a lot of small diodes in parallel so I will try to get one and
see if it aggregates rectified Johnson noise in the dark.
Aloha, Charlie
