Joule Thief

[Mk1]

@ist

That's the sunbeam 9w cfl circuit?

[gyulasun]

....snip
After reading a post from @gyulasun on page 324, wich i'll admit i don't fully understand.
( i have trouble understanding something i can't see e.g. the JT, i see the light come on,
i can't see  the magnetic field, the transistor switching, the capacitor charging/discharging,
and so on, ) I thought i'd try something different.

I started with 16 turns primary, 4 turns secondry wich gave me 7vdc 12ma and 42ma draw from battery,

I then wound a third winding, one end went to the collector after a diode, and the LED went between
the emitter and the other end of the third winding, after some tuning i ended up with
8 turns primary, 2 turns secondary and 12 turns for the third winding,
results were - 21vdc 27ma and 39 ma draw from the battery.
....snip

@mikem_2au

Hi,

I can assure you I cannot see magnetic field either      and if you wish something to explain further I will if I can.

I do not know if others here also noticed but I like your numbers on the DC voltages and currents because they reflect higher than one output-input ratio...    Have you double checked them?

Assuming 1.5V battery voltage @ 42mA  current draw, your input power is 1.5 x 42=63mW  and your output power is 7V x 12mA=84mW.   You seem to have a COP (coefficience of performance) of  84/63=1.33 !!

Your other setup's input power (with the third winding) is 1.5V x 39mA=58.5mW and the output here is 21V x 27mA=567mW,  the COP is 567/58.5=9.69   (mW !)   EDIT: sorry for the mW, COP has no measurement unit, it is a ratio.

Congratulations for these results and I hope your DMM does not let you in...

Maybe you could share some tricks how to achieve these excellent results.

Regards,  Gyula

[hazens1]

I hooked a 3v airhogs biplane motor in series with my 40-50 turn bobbin coil. Brightness stayed the same and current draw went down to ~20ma and the motor is spinning now too. That's the same amout of light for 30ma less than the previous circuit. I turn the leds off and let the timer circuit run alone and the motor stops and current draw goes down to ~8ma. If I stop the motor with my fingers with the leds on, the leds brighten by 200% and the motor has some torque to it and ma draw goes up to 40ma. That's 2x the light for 10ma less than the previous circuit.

Voltage went from 3.002v to 2.977 in dropping 0.025v in 60 minutes.

[Mk1]

@gyulasun

Hi and welcome!

The idea is magnets , like a stator in a motor doesn't move but creates illusion of movement, it still works , but classic theory on how it works are naive but the real stuff is even harder to believe , so i wont go fully there, but lets say it a simple step up transformer , on a saturable core that is magic because has the core saturates the coil inductance also changes , the impedance is reduce in a big way . the basic is creating pulse in a coil , in a normal strait core both ends of the straight core are creating magnetic field basic electromagnet there , but when you do in a toroid that magnetic flux stay in the core , so the fields feed each other, Now the coil there is usually the same current trough all the coils , but in classic theory the voltage output is higher but amps lower then the input , but they only count up to 2 coils , but the law is the same with 3 4 5 6 9 10 coils , same current in all coil ? that is if you think outside of the box. Now how to get a good design that is the question?

Also the magnetic effect on the toroid like the electromagnet , the iron in there is not a magnet , but put it under electrical stress and the metal will try to adjust generating first the magnetic effect but also excess energy , that is where the fun is . The excess energy is only transmited when the coil is shut down .
i wonder is regular magnets work in space?


Mark

I hope this helps !

[jadaro2600]

SO the other day I got the circuit to run as usual, but it was brighter - I used a green LED.  I removed the resistor and the circuit continued to run without there being a path from positive to the beginning of the capacitor.  In other words, the circuit may have looked like this - and I have been unable to replicate the accident.

I was wondering if anyone had any ideas?