To be deleted

[nul-points]

Cerdos Voladores!

Hah  - that's a close call !

Well, the datalog results below, for the Flyback Flash-lite test run, show that it operated for 14.5 hours (for the same supply drop, using the same load, and set to the same initial temperature differential as the DC drive run)

So this pulse circuit operated for an extra 45minutes, heating the same output load to the same level as the DC circuit (as monitored for at least the first half of its run duration)

Further testing will be required to confirm its performance, but the results are very promising

More to follow
np

[nul-points]

Flyback Flash-lite test, 9th Feb '16:-

Use Flyback Flash-lite circuit supplied by 3x NiMH 750mAh cells (battery 'A') to charge 3x emptied NiMH 750mAh cells (battery 'B') in series with 50 ohm resistor; output from circuit via a BAT42 Schottky diode (see schematic above, Reply #5)

The 50 ohm resistor/ series diode arrangement is 'standing-in' for an LED head, to help quantify some test values; it presents a comparable load level in its own right, energy-wise, and it demonstrates the underlying principle of this Flyback Flashlight operation that, since work is not conserved,  the same energy can be used more than once, en route to the Entropy trashbin


Datalog results attached below, show discharge voltage profile for battery A (red trace), and charging voltage profile for battery B (blue trace)

Previous results posted above (Reply #9) show discharge profile for fully-charged battery A:-
(Straight DC drive of 50 ohm resistor in series with BAT42 diode)

Approx. avg. supply volts:  ((4.25-3.3)/2)+3.3  = 3.77V

Approx. volts drop across series BAT42: 0.3V

Approx discharge current: 3.47/50 = 69.5 mA

Load power:  (0.3 + 3.47) x  69.5 = 262 mW

Runtime duration: 13.75 hrs

Supply energy (NiMH): 262 x 13.75 = 3600 mWh

Back calc. of NiMH mAh: 
  energy per cell = 3600 / 3 = 1200 mWh
  av volts per cell = 3.77 / 3 = 1.26V
cell capacity = 1200 / 1.26  = 950 mAh


The same DC discharge test procedure was then used to determine the amount of energy transferred to battery B, in this latest test below (using relative discharge time into same load as for fully-charged battery A, above)

DC discharge duration test of Battery B (via 50 ohm / BAT42 in series):  5.5 hours  (from 4.2V to 3.3V) approx

Approx. Energy in Batt B:  (5.5 / 13.75) x 3600 = 1440 mWh

Coulometric charging efficiency of NiMHs:  70% approx
(source: Powerstream.com)

Approx charge input energy:  1440 / 0.70 = 2060 mWh

Approx energy transferred via 50 ohm/ BAT42 : 2060 mWh
(because this series load transferred all the energy used to charge battery B)

approx COP of Flyback Flash-lite when charging battery B, from empty, and heating 50 ohm resistor, from fully-charged battery A
(2 x 2060)  / 3600 = 1.14

(ie. an Efficiency of 114%)


NB.  i shouldn't have to spell this out, but we *do* have some er, 'excitable' members (on both sides of the Unity fence) so, E&OE, YMMV, Caveat Emptor, etc, etc - these are 'ballpark' figures - the clue is in the hefty use of the term 'approx'

np

[nul-points]

Hello reader

...an interesting development here at Flyback Fortress

First, some context...

One of my early projects, back in 2007, when i started to get interested in FE,  was the Jensen Unidirectional Transformer (UDT)

There wasn't much info about it, and since i didn't have any transformer core laminations at the time, i decided to try and create a toroid version using EMI ferrites

(NB. This was about a year before Mr Heins hit the scene with his BiToroidTransformer)

I'm not proud of my build quality then, but the 'Triformer' was born - see photo below for that first version (3x thin toroids)

[Edit 1] added photo of more recent Triformer, 2x thin primary toroids, 1x thick secondary toroid (T Heins recommended this improvement to my original 2007 version); similar to current Flyback flash-lite test run, but without conventional secondary mod


Although Mr Jensen's notes seemed to suggest that the UDT be used with AC waveforms, i've only ever used the Triformer with pulsed DC waveforms

The only time, before now, that i've seen any benefit from the Triformer configuration, was when i used it with a flyback oscillator to charge batteries from a solar panel - keeping all other settings the same, the charge current could be increased just by shorting an unused winding

Ok - you've guessed it - i've now decided to try one of my Triformers with the Flyback flash-lite circuit

On this version of the Triformer i've added a conventional secondary over the top of the primary, this leaves two secondaries available at the junctions with the primary toroids and the 3rd toroid

2nd test still in progress (because its runtime has been extended by at least a day!) - 1st test runtime lasted 24 hours illuminating a 1W LED using a 2x 750mAh cell NiMH battery with the Triformer connected as a conventional transformer

On this 2nd run i repeated the test but shorted both secondaries - so far, the circuit has been illuminating the same LED for nearly 40 hours and looks like it could double the runtime of the 1st test!

When i started the 2nd run, i wasn't expecting anything significant, so i'll need to rerun these two tests and include the photometer output in the datalog results, to check if the extended runtime has been traded off against illumination level

More later
np

[Edit 2]  Test run 2 has just completed - 48 hours (double the runtime than with secondaries unshorted) - datalog traces of battery discharge below -  Unshorted Test :   0-24hrs;  Shorted Test starts @ 24hrs, finishes @ 72hrs

i'm rerunning those tests now with photometer readings added - i'll try & adjust the shorted test power to give equivalent illumination to compare runtimes directly

np

[PARAV]

Hi nul-points,


I have been eagerly watching and waiting for your latest test which I think was showing some real promise with the " triformer".


Please let us know how it's going and give us an update.


Thanx in advance--Paul

[nul-points]

I have been eagerly watching and waiting for your latest test which I think was showing some real promise with the " triformer".

Please let us know how it's going and give us an update.

Thanx in advance--Paul

Hi Paul, apologies for the delay - interesting things seen with the Triformer, so i'm now backtracking and trying it with some of the flyback flashlite circuit variants which i've explored & parked

I'll post updates again asap

thanks for your interest ...and Hi to all the other folk quietly watching this thread in the background - appreciated!
np