Lasersaber strikes again. A joule thief king ?

[conradelektro]

I lifted TinselKoala's DALM circuit diagram from his video:

http://www.youtube.com/watch?v=4tMwntAO_cI (at minute 4:30)

Greetings, Conrad

P.S: will be back in a few days

[TinselKoala]

Well, thanks! But I could have posted the schematic if you really needed it. We did a whole thread on Dark Alchemist's neat little circuits last year some time.
Enjoy your time off!

[madsatbg]

http://youtu.be/jbBroLeXl_4

[Vortex1]

The Max 931 is a great little part and can do wonders at low voltage, especially when you reduce the 1k so it is not eating power. At higher voltages however the 1k current limit resistor alone will be eating half to two thirds of the switching power, depending on the Vdrop of the LED.

The part itself consumes very low power so for most applications it is a good fit. For efficient operation at higher voltages a simple properly designed flyback converter may crossover into becoming a better fit.

Much also depends on the intended final use and production criteria i.e. are we designing a cost no object "one off" for our own use or will it be produced by the millions and cost of components is extremely critical? And how big a factor is squeezing the last bit of power consumption out of the design vs. cost?

Earlier in this thread (post 111) I posted a simple two transistor multivibrator flyback converter that uses a single cheap inductor that can't be beat for cost, but may consume a bit more power. It does, however, work down to less than one volt and adjusts its duty cycle to suck the last bit out of a single battery cell . I have not tried to optimize that circuit for low power. Will do when I get back to the bench.

So there are many tradeoffs.

Regards, Vortex1

[Preva]

Hello



http://youtu.be/uTc8at-dJhk