To be deleted

[nul-points]

...flyback flash-lite configuration...

[nul-points]

...Itsu replication - I/p, o/p & LED power traces...

[nul-points]

...comparison of Illumination intensity vs runtime; both using 3x 750mAh NiMH & commercial 24 white LED head- a) commercial flashlight (straight DC drive) - b) np flyback flash-lite drive - runtime of flyback flash lite is 10 hours vs commercial flashlight at 5 hours...

[nul-points]

Flyback 'Vampyre' circuit variant; sucks out the last drops of energy from 'Used' primary cells - and transfers the energy into secondary (rechargeable) batteries

Can also be used with solar cell i/p to trickle charge storage devices

Photo below shows circuit being used to drain a discarded AA 1.5V alkaline cell, and transfer the energy to an 8.4V NiMH battery

C1 - 100uF 16VTantalum;
VR1 - multi-turn 10K Varpot;
Q1 - low power, hi-gain NPN transistor, eg. BC547, BC337, etc;
D1 -  low-leakage Schottky diode, eg. BAT 42;
T1 - approx 40:120 turns magnet wire on ferrite toroid;
device shown uses EMI filter split-ferrite core, approx 25mm OD, 10mm high with 9-filar x 0.09mm litz
(mono-filament wire ok, just keep pri:sec ratio approx 1:3)

[nul-points]

Start of comparative tests between straight DC drive of a compound resistive load
and pulse drive of the same load, using the same fully-charged NiMH batteries and the
Flyback Flash-lite circuit

These results will give an indication of the efficiency of this pulse circuit compared to
a benchmark of the equivalent amount of DC energy converted

The compound load is a multiple-watt, ceramic-encased, 50ohm resistor, in series with
a BAT42 Schottky diode. The diode & resistor are pressed together in close proximity
with a temperature probe, completely encased inside approx 18mm (0.75") thick
compressed paper insulation

The datalog of the DC test run shows that the fully charged NiMH battery (3x 750 mAh cells)
was able to provide power to the load for approx 13.75 hours over a voltage range of 4.3 to 3.3V
(ie. fully-charged to fully-discharged)

The DC test was able to achieve a maximum of approximately 13.5 degF of temperature differential
over ambient (the temperature-differential profile for the complete test run, of course,
varied slightly as the battery voltage decreased with discharge)

The next test will be to operate the Flyback Flash-lite cicuit with the same insulated load,
powered by the same fully-charged NiMH cells (having adjusted the power level of the circuit
to give a similar initial load-temperature rise over ambient) and compare the run duration
with that of the DC test

IF (and this is a big 'if'!) this pulse circuit could deliver the same level of heat at the load for
the same duration as the straight DC drive achieved, then the circuit would be 100% efficient.
This in itself would be a remarkable achievement

If the circuit can match the same level of heat as the DC drive, but for less time,
then the pulse circit will be underunity (ie. some level of efficiency less than 100% - situation normal)

Moving into the realm of flying pigs, if the circuit can match the same level of heat as
the DC drive, but for a longer duration, then the pulse circit will have provided
evidence of overunity operation

Mesdames et messieurs, faites vos jeux...

(results of comparative test should be ready towards the end of today, GMT, Tuesday 9th Feb)

np