3v OU Flashlight

[Farmhand]

Tinsel, I have a question, I have two quite small 3.7 volt 20 mAh batteries from a couple of busted power meters, they would fit easily into a fairly small pot and I can imagine how to wire it as well. The question is - How long do you think a small battery like that could light up a string of say 6 x 5 mm white LED's if I used very small pulses to a coil at about 20 Hz and used the discharge to light the LED's ? I think quite a while, but maybe not. I could maybe fit two into one pot, then connect the terminals to two of the pins of the pot and solder the pins to the rail, some way to trigger it to start and hey presto. I guess the pot can be a switch as well, hahahaha.

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[verpies]

Attention to details clearly isn't your forte.

It is hard to see the details.  I simply cannot read digits on the scope's display, not to mention the markings on the ICs of an unknown circuit

[Kator01]

Hello,

Chris Sykes ( Hyig.org) has posted a vid:

http://www.youtube.com/watch?v=7eJevE1FEas

Regards

Kator01

[TinselKoala]

Tinsel, I have a question, I have two quite small 3.7 volt 20 mAh batteries from a couple of busted power meters, they would fit easily into a fairly small pot and I can imagine how to wire it as well. The question is - How long do you think a small battery like that could light up a string of say 6 x 5 mm white LED's if I used very small pulses to a coil at about 20 Hz and used the discharge to light the LED's ? I think quite a while, but maybe not. I could maybe fit two into one pot, then connect the terminals to two of the pins of the pot and solder the pins to the rail, some way to trigger it to start and hey presto. I guess the pot can be a switch as well, hahahaha.

..

I showed the full "3V" circuit running for a long time on a single thin CR2016 button cell here:
http://www.youtube.com/watch?v=NZFSnLgXfQE
and if you use "Joule Thief" technology you can light up your 6 LEDs for even longer than shown in that video. Triggering it with a touch is easy, as TinMan has demonstrated. Many JT variants need a little "tickle" to start oscillating and this behaviour can be "tuned" into just about any JT variant circuit by careful choice of component values.
Ironically... many of my own JT circuits work _better_ if you use two or more LEDs _in series_ as the load. The DALM variant with four blue LEDs has them all in series, and it runs for many minutes on a single tiny AG1-LR621 button cell.

I can think of no other good reason that Akula's pots... only two of them, not all.... have their cases soldered to the negative "ground" rail of that circuit. I think there is a good chance that he has batteries in there. But also.... very fine magnet wire, like #32 and below, will not show up on videos made for YouTube, and are plenty sturdy enough to allow powering LEDs and even some incandescent loads from an out-of-frame power source.

[TinselKoala]

Two signal generators can be used together to produce interesting effects. Usually there will be a "trigger/synch" output and a "trigger" or "gate" input. You can use one signal generator to "gate" or trigger the other one's signal, so in effect you can set up the same kinds of "beating" from two frequencies that the dual 494 and similar circuits use. My old F43 even has a "VCF" voltage-controlled frequency input so that a second voltage source (like another FG) can control the frequency of the F43, in addition to the gating and phase-locking capabilities.
Even signal generators without these explicit input-output hookups can still be "daisy-chained" by connecting their outputs in series, so that one oscillation is superimposed on the other one.