PhysicsProf Steven E. Jones circuit shows 8x overunity ?

[nul-points]

 
good morning Steven


i've been running my SJ1 variant tests from a single  (depleted) AAA NiMH, and the voltage has been around the 1.12-1.15V range

just for fun i constructed another unit to add to the comparative results you're getting back from folks

the circuit is a minor mod to one of my earlier tests with a variant of your SJ1 circuit (see schematic below for this test circuit)

C1 0.022uF
D1 1N5817 (schottky)
Q1 2N3906
T1 approx 50:50:100; 0.45mm wire; tri-toroid (ferrite)
C2 1000uF (nominal)
L1 approx 0.5mH
LED1 6mm(?) HiBrite (visible, but not bright)

i'm using a tertiary winding to decouple the AC o/p from the DC operating conditions of the oscillator


this circuit takes 433 seconds (7min 13sec) to discharge a nominal 1000uF cap from 2.24V to 1.5V

C2 1000uF (nominal)
2.24V => 2.509mJ
1.50V => 1.125mJ
         -------
    Ein: 1.384mJ

Pav: 1.384/433 = 3.2uW


this is all just ballpark at the moment, obviously - to be more accurate, the 1000uF cap would need measuring

also, the pulse repetition frequency is outside your stated conditions, so this circuit doesn't qualify for your competition

it starts at approx 28Hz, with no visible flicker, and the frequency increases as the supply voltage falls

the pulse 'burst' is approx 15uS long


since i have the o/p DC decoupled with the tertiary wind, i can now revert back to the NPN config of your original SJ1, so i'll be able compare efficiency between the two

[EDIT:  i'll also try with a 1N4148 (& then a schottky) replacing the LED, to see the effect on discharge time]


on the subject of the lower frequency limit for your stated conditions, i feel that in general, any frequency of LED drive which the eye perceives as 'continuous' should be counted in - this would be one of the 'design limits' for a commercial lighting product

i agree that care would be needed, in these tests, to ensure isolation from utility & broadcast sources of 'ambient' energy,  but it's not difficult to discount these other sources of input by using a metal case, or taking measurements with the device in a microwave oven

in fact, with wi-fi, bluetooth and cordless phone signals around the home this sort of shielding will likely be advisable anyway, in which case the lower frequency limit does not need to start at 200Hz

just my 2c


good idea to start a competition, looking forward to seeing how this develops!


greetings
np

[EDIT: corrected D1 partnum.]


http://docsfreelunch.blogspot.com

[poynt99]

BTW, .99, the sentence you quoted was from a separate discussion on a different forum altogether!  which you neglected to link or even mention....  isn't that a bit odd?

It was laziness. Don't read too much else into it.

I think the criteria for the contest -- discussed ONLY in this forum -- have been clear all along, including the provision for an observable LED in the circuit, replaced by a 1N4148 diode for a final test using the cap/time method (for the contest).

imho, you will not be able to accurately make comparisons this way, and jmmac has not only reiterated this, but shown this with his post.

http://www.overunity.com/index.php?topic=10773.msg291482#msg291482

In order to make fair comparisons, the Vbat and Pout must be the same in each case, then you measure Pin with your method and compare. LED intensity will not enable proper comparisons, even if substituted with a diode afterward.

.99

[JouleSeeker]

Hi Professor,

I bought some components i was missing and was able to replicate your circuit. It now shows waveforms similar to yours - input current and power oscillating around zero.

Using a 10mF capacitor instead of a battery, i let the circuit run and the capacitor discharged from 2.48V to 1.50V in 104s which i believe gives an average input power of 37uW.
For this setup i used a 2N2222 transistor, Cb = 151pF, Rb = 1MOhm, Ro = 0. The led is red, very bright and needs very little current to light up. It was very visible as shown in the picture. The other picture shows part of a cycle of the input current. The frequency is around 10.6Khz made of very short pulses. I didn't measure the real capacitance of the 10mF capacitor which may have a higher value.

If i try the same setup but change the transistor with the 2N3904, the led is dimmer but perfectly visible and the capacitor discharges in 296 seconds which i believe corresponds to an average power of 13.18uW.

I'm not sure we can conclude much from these results and it's very difficult to compare results from different experimenters since there is no way to measure the led brightness. If i use the diode i get similar discharge times (a little longer).

I also tried running the circuit from the capacitor and charge a second 10mF capacitor via a schottky diode. I let the source capacitor discharge to 1.50V and at that point disconnected the charging capacitor. Calculating Ein and Eout, n is around 0.42.

Regards,
Jaime


EDIT: The coil has 20-21 turns in the primary and secondary with what appears to be a normal ferrite toroidal core. The inductance is unkown.

Thank you for doing the replication AND the cap/time method test, Jaime!

1.  "I'm not sure we can conclude much from these results and it's very difficult to compare results from different experimenters since there is no way to measure the led brightness. If i use the diode i get similar discharge times (a little longer)." 
  The use of a common diode like the 1N4148 allows us to make direct comparisons between different experimenters; we don't have to measure the LED brightness!
   @Xee2-  your suggestion of another "standard" diode Rk44 is noted; let me try it out experimentally and see how it differs.  The 1N4148 is so common, that provides some advantage for a "standard input-power test" .

2.  I need to check your numbers; pls spell out the algebra in the future -- that would help to see where there may be a discrepancy.  I get:

Ecap = 1/2 C V**2
so
Pinput = 1/2 C (Vstart**2 - Vstop**2)/time

With your numbers,
Pinput = 1/2 C (2.48**2 - 1.5**2)/time
          = 1/2 * 10mF * (6.15-2.25)/time
          = 19.5mJ/104s
          = 0.188mW = 188 uW  (not 37uW -- pls re-check)

For your longer discharge time, 296 s, I get
Pinput = 19.5mJ/296 s =66uW

Please re-check the numbers, would you?  we should agree on the calculated average input power.

Also, I note that with a charging cap on the output leg I typically found n~0.5-0.7 so we're not far different.  Of course, this method for Pout neglects the power dissipated in the LED (and other components), but is a first estimate (as I noted earlier).  Thanks for doing this test.

Important:  what was the POLARITY on this output cap (compared with the direction of the LED)?

[JouleSeeker]

It was laziness. Don't read too much else into it.
imho, you will not be able to accurately make comparisons this way, and jmmac has not only reiterated this, but shown this with his post.

http://www.overunity.com/index.php?topic=10773.msg291482#msg291482

In order to make fair comparisons, the Vbat and Pout must be the same in each case, then you measure Pin with your method and compare. LED intensity will not enable proper comparisons, even if substituted with a diode afterward.

.99

Laziness it is then -- but pls explain why using a standard diode at the end will not give a basis for comparisons of Pinput FOR THIS CONTEST.  (AGAIN, I'm asking you not to confuse the contest goal with the separate goal of measuring Pout and efficiency n.) 

[JouleSeeker]

good morning Steven


i've been running my SJ1 variant tests from a single  (depleted) AAA NiMH, and the voltage has been around the 1.12-1.15V range

just for fun i constructed another unit to add to the comparative results you're getting back from folks

the circuit is a minor mod to one of my earlier tests with a variant of your SJ1 circuit (see schematic below for this test circuit)

C1 0.022uF
D1 1N5187 (schottky)
Q1 2N3906
T1 approx 50:50:100; 0.45mm wire; tri-toroid (ferrite)
C2 1000uF (nominal)
L1 approx 0.5mH
LED1 6mm(?) HiBrite (visible, but not bright)

i'm using a tertiary winding to decouple the AC o/p from the DC operating conditions of the oscillator


this circuit takes 433 seconds (7min 13sec) to discharge a nominal 1000uF cap from 2.24V to 1.5V

C2 1000uF (nominal)
2.24V => 2.509mJ
1.50V => 1.125mJ
         -------
    Ein: 1.384mJ

Pav: 1.384/433 = 3.2uW


this is all just ballbark at the moment, obviously - to be more accurate, the 1000uF cap would need measuring

also, the pulse repetition frequency is outside your stated conditions, so this circuit doesn't qualify for your competition

it starts at approx 28Hz, with no visible flicker, and the frequency increases as the supply voltage falls

the pulse 'burst' is approx 15uS long


since i have the o/p DC decoupled with the tertiary wind, i can now revert back to the NPN config of your original SJ1, so i'll be able compare efficiency between the two

[EDIT:  i'll also try with a 1N4148 (& then a schottky) replacing the LED, to see the effect on discharge time]


on the subject of the lower frequency limit for your stated conditions, i feel that in general, any frequency of LED drive which the eye perceives as 'continuous' should be counted in - this would be one of the 'design limits' for a commercial lighting product

i agree that care would be needed, in these tests, to ensure isolation from utility & broadcast sources of 'ambient' energy,  but it's not difficult to discount these other sources of input by using a metal case, or taking measurements with the device in a microwave oven

in fact, with wi-fi, bluetooth and cordless phone signals around the home this sort of shielding will likely be advisable anyway, in which case the lower frequency limit does not need to start at 200Hz

just my 2c


good idea to start a competition, looking forward to seeing how this develops!


greetings
np


http://docsfreelunch.blogspot.com

Impressive work, nul-pts!  very good.
And I agree with your numbers, which are amazingly low (3.2uW) --

Ecap = 1/2 C V**2
so
Pinput = 1/2 C (Vstart**2 - Vstop**2)/time
   = 1/2  1mF  (2.24**2 - 1.5**2)/433 s
   = 3.2 uW

Wow!  Very impressive.  I also agree with your argument that 28 Hz is OK -- and I'm going to drop the minimum 200 Hz requirement, with the proviso that 60 Hz is NOT OK (50Hz in Europe and much of Asia)...  and I would like to see a test of your device in a Faraday cage!  that would be interesting in itself.  E.g. a microwave oven (OFF!) should allow you to see and time the voltage drop...  yes, with the DMM inside the cavity also.


I have found, as did Jmmac, that replacing the LED with a 1N4148 diode for a standard changes the Pinput somewhat, but not much -- suggesting to me that our eye-ball estimate of a "dim LED" is not bad.  Still, would appreciate it if you would repeat the test with a 1N4148 if you would, and also if you would try to start at about 2.5 - 2.6 V...  You can start with 2 fresh AA's and run the circuit down to approximately 2.55 V then stop, and you're prepared for the "standard" starting voltage of close to 2.55V.