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Author Topic: Single AA battery to light WHITE LED for long-long time  (Read 185275 times)

bolt

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #135 on: March 28, 2008, 05:24:17 AM »
Looks a total waste of time to me. The circuit is just a simple oscillator with the L being the core and C is the stray capacitance of the circuit which means it will oscillate at many megs. The  transformer coupling has been done in RF stages for 100 years nothing fancy going on here at all. What you will get is "mystery" readings as you start to increase power RF will get back into you DVM and convince you have have found extra power. If you do this with a power fet some will easily put out 5 watts of RF run on 12 volts and they will splutter up and down the band and make a lovely jammer for miles around!

If you start making spark gaps you will create havoc with TV's and radio and you wont be popular with your neighbors.

If you want to light up the LED with no battery make a simple tuned circuit. Ground one end and stick an aerial wire on about 150ft long thin copper wire then tune the output into an LED. It will light up from strong AM radio stations for FREE :) 

But this is all kids stuff i did all this when i was about 7.

BTW the battery starting low and increasing is well documented due to partial oxidation of the cell plates on standing. As you start to draw current this oxi layer burns off increasing plate area and the voltage comes up a tad then drops later as the battery is used. Lithium batteries suffer badly from this effect.

Groundloop

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #136 on: March 28, 2008, 12:33:58 PM »
@Bolt,

I started to play with electronic at the age of 9. Now, at 50 I'm still learning new things.  ;D
Many of the members on this forum plays with these circuits as a hobby. I think most of
them also think this is fun. Personally, I think that ANY hobby is NOT a waste of time.

Quote
BTW the battery starting low and increasing is well documented due to partial oxidation of the cell plates on standing. As you start to draw current this oxi layer burns off increasing plate area and the voltage comes up a tad then drops later as the battery is used. Lithium batteries suffer badly from this effect.

Can you provide a reference to your statement?

Groundloop.

Drossen

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #137 on: March 28, 2008, 02:43:53 PM »
Do you want to know what happens when you boil the acid in a battery?  Well, I just happen to have first hand experience with this.  When I was a teenager, I was playing with batteries, and just happened to make the mistake of heating one up to the point where it started to boil inside.  After several minutes of hearing the acid boil, I noticed that the battery was bulging, and after a few more minutes it exploded.  Hot acid and pieces of battery flew everywhere.  The acid ate wholes in my clothes, and I received second degree burns from the heat of the acid, not to mention the additional burn caused by the acid eating at my skin.  It was not cool!!  If you want to try boiling the acid in a battery, I would highly advise against it.

Drossen

MrMag

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #138 on: March 28, 2008, 04:12:15 PM »
Sorry guys, I may be out of line but I just came across this thread and really haven't read it through so shouldn't really comment but.....

Are any of you out there Pink Floyd fans? I purchased their Pulse CD many years ago. What they had on the CD case was a red LED that pulsed. I am pretty sure I had to pull out the little plastic tab to get it started. This LED pulsed on at a slow rate ( ~.5 sec on - ~2 sec off) but it pulsed for over 4 years without changing the battery. I couldn't believe that it would have lasted that long!

Tim

Feynman

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #139 on: March 28, 2008, 04:24:00 PM »
Pink Floyd fan here...

The duration of the LED doesn't surprise me too much... depending on the type of battery a little LED can go a long time.   What's interesting about the joule thief circuit, however, is the high voltage transient occurring in a coil which is wound 1:1.  There may be a good conventional explanation, but I think the waveform and circuit operation are very interesting. Especially the 20V I was measuring on one of the coils, coming from a sub-1V battery.  This may all be conventional , but I didn't know this was possible until I built it.  I still haven't gotten around to doing the full scope traces around the circuit or creating the spark gap because of all the other stuff, but I hope to have some time soon.

@Bolt
You mean to tell me a tiny sub-mm spark gap is going to wreak havoc on my neighbors reception?  I've gotta build this!    :D





bolt

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #140 on: March 28, 2008, 04:34:08 PM »
Passivation
     

Passivation is a very thin, high resistant,self-assembled layer formed on the surface of the lithium anode. It is formed as a result of a chemical reaction between the battery electrolyte and the lithium anode. Without the passivation layer, this type of lithium battery would not exist because the lithium would discharge and degrade quite rapidly. An advantage of the passivation layer is it allows the battery to have a very low self discharge rate and extremely long shelf life.
     The most obvious affect of the passivation layer is voltage delay. Voltage delay will occur when a load is placed on the cell as illustrated in the following drawing:
     
     After a load is applied to a cell, the high resistance of the passivation layer causes the cell's voltage to drop rapidily. The discharge reaction slowly removes the passivation layer thereby lowering the internal resistance of the cell. This in turn causes the cell's voltage to reach a peak value which should remain steady if other discharge conditions do not change. If the load increases after the cell's voltage stabilizes, then it may drop again until the passivation layer is fully removed.
     Once the load is removed or lowered, the passivation layer will reform, and voltage delay may be a factor when subsequent loads are applied.

Almost all batteries suffer some kind of paasivation problem some worse then others. Alkaline batteries have a very noticeable effect if they been on the shelf for months when first used they plummet and take many minutes to kick into life.  Google passivation for more info but i had to study this many years ago when developing low power RF solutions using lithium and getting circuits to run on a couple of micro amps. When the circuit is right you can flash an LED and run an RF transmitter on a single AA cell for EIGHT years.

Jack will know about this too i bet he followed a similar design path with his cart locking wheel.

Groundloop

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #141 on: March 29, 2008, 12:50:30 AM »
@bolt,

Thank you for the explanation on passivation. Passivation causes a drop in battery voltage when the battery is loaded after a period of storage.  When the battery is loaded the passivation layer will be converted to other material and the battery is then at full capacity again.

See, I learned some new stuff today.  ;D

Thanks,
Groundloop.


amigo

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #142 on: March 29, 2008, 01:19:05 AM »
@bolt,

Thank you for joining our thread and giving us your opinion. It is sad that you did not illuminate the thread with some good ideas or supportive suggestions since you portrayed yourself as an expert.

If we are to take your advice we should all just eat the gun and forget the whole thing of living/being alive. After all why the hell bother for when it's all a waste of time...right?

The age old advice I'll dispense back to you is if you have nothing good, positive or supportive to say, just keep your mouth shut.

Thanks again !

Goat

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #143 on: March 29, 2008, 01:26:33 AM »
Hi all;

Regarding the spark gap.

Thought I'd mention one way I found to make an adjustable spark gap a while back.

Break the glass off of a NE2 bulb (use a piece of cloth over the glass and gentle pressure from a pair of needle nose pliers) and then adjust the anode and cathode (to as close as you can get them) and attaching the two leads to the high voltage end.

I found that using a piece of thin paper between the anode and cathode when adjusting the gap you can use the paper as a feeler gauge to get the spacing as close as possible.

The advantage I found of doing this as that the anode and cathode seem not to burn with high voltage compared to other types of metals..

Regards,
Paul


Groundloop

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #144 on: March 29, 2008, 02:35:13 AM »
@Goat, @All,

The dielectric strength of air is approximately 3 kV/mm. Lets say we want to make a spark gap
to run our circuit (instead of a transistor). For 3 Volt spark gap the gap itself must be approx. 3um.
Three micro meter is 3mm / 1000. Do you think it is possible to make such a small spark gap with
your neon bulb method?

Thanks,
Groundloop.

Feynman

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #145 on: March 29, 2008, 03:03:56 AM »
@goat

Thank you for the information; that's a really good idea.

@groundloop
Nice math !

I think Goat's neon bulb is a great idea for higher voltages;  personally  I like marco's "mechanical pencil" graphite method for the lower voltages (<20V) because 1) graphite resistance is basically like 1 ohm per cm according to my experiments. . . 2) one can line up the graphite under a microscope, and then once the gap is precisely calibrated using a grid, one can easily glue the graphite to the surface using two drops of superglue (cyanoacrylate i think).

Of course, this require a microscope  ;)   but I am working on that part...  maybe more sneaking into labs late night at night.   ;D

Goat

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #146 on: March 29, 2008, 03:36:45 AM »
@ Groundloop & All

I did not mean to say that the NE2 electrodes are better than the "mechanical pencil" graphite.  All that was meant by my post is an alternative method of making a spark gap.

As far as the "3 Volt spark gap" you mention, I have not seen the circuit that Marco has mentioned as the following in a previous post on this thread:

"I have played with many of these types of devices a couple of years ago and as they are presented here they are not OU devices.  But they can be."

Then he mentioned the spark gap.

Although spark gaps are quite visible at high voltages I have yet to make a continuous spark gap at 3 Volts or even 12 Volts!  Unless it's when you first hook up the last terminal of the battery to the correctly laid out circuit (meaning precise impedance) for the load to power source ratio and frequency.

Maybe I'm asking to be spoon fed by saying this but Marco if you're seeing this dis-agreement between me and Groundloop as a moot point please "Pray Tell" because I do not wish to alienate Groundloop and I in further discussions, could you please post what you meant by spark gap?  Was it used in your OU circuits at low or high voltage(s)?

With all regards for everyone,
Paul

Goat

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #147 on: March 29, 2008, 04:02:50 AM »
@ Feynman

I'm wondering, could you try to find out what the resistance of the NE2 electrodes would be compare to the graphite?

If anyone else on the forum knows about this please reply.

Just curious as I'm not able to find out what the cathode and anode of the NE2 are made of and their resistance and breakdown voltage.

Regards,
Paul

amigo

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #148 on: March 29, 2008, 04:03:46 AM »
Goat, good idea about the NE2, it's probably worth a try.

I was thinking about the graphite spark gap and to use the piece of paper as a separator. The only problem I'm trying to resolve is mounting the two bits of graphite and connecting them to wire. I suppose we can glue the wire to the ends of the graphite and then glue the graphite as Feynman proposes.

We could use a human hair to space out the ends, it being about 50um in diameter it's not too bad but not that close to 3um either. Still better than nothing for the time being, and could probably be done with a magnifying glass instead of a microscope. :)

Pirate88179

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Re: Single AA battery to light WHITE LED for long-long time
« Reply #149 on: March 29, 2008, 04:48:23 AM »
Just for reference:

A human hair is .003" dia.  A piece of paper (copier type light weight) is about .002"

Bill