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 Post subject: Perpetual power?
PostPosted: Oct Sat 19, 2019 7:51 am 
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Some years ago I found this simple transistor astable muli-vibrator circuit schematic online.
Image

I built it using some modern npn transistors that I found laying around and when connected to a 9v battery it would operate for about a month depending on the value of the components chosen.

About a year or so ago I wanted to fiddle with it again ... so this time I used two antique TI904 npn transistors from the 1960s
https://www.radiomuseum.org/tubes/tube_ti904.html

I also used two led lights( a blue and a yellow)
So I had to vary the part values slightly to get it to blink fairly evenly at about twice a second or so.

I put a used 9volt battery on it that I must have taken out of my old garage door remote-opener or a smoke alarm ( it has a date code on the bottom 1105A ... what ever that means.
( (Die Hard brand)
Anyway it blinked steadily for at least a few months.. or so .. maybe more.

So... for fun... I hung the circuit and battery from a paperclip hook on my ceiling over my desk and just let it hang there undisturbed while it blinks steadily.

Then as the battery drained down, I noticed that it was barely blinking anymore.

Eventually it wasn't even blinking at all ....but the two leds just sort-of dimly glowed.

So for the last 6 weeks or so I'd glance up at it and see those dim leds barely glowing.... and so, I figured it was about to drain the battery totally flat and then the two leds would just eventually extinguish completely.

But no.

Yesterday I looked up at it and... WOW ... both leds were back to fully lit and blinking as though I put in a new battery!! But I didn't.
So sure enough... it's still going brighltly and blinking strong...
YEP ...blinking brightly again and no sign of getting dim. lol

I haven't even touched it at all.... just hanging there.

So what is going on?

How could the circuit (appear to) drain itself almost flat with dim barely lit leds for weeks... and then suddenly rejuvenate itself?

I've never heard of anything like it?

Now... I have heard that led bulbs are also solar light voltage generators or something... ( is that true?)
Could it have recharged the batteries from the light in the room?
I know it makes no sense... but it's blinking like hell... lol

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Last edited by Pbpix on Oct Sun 20, 2019 5:11 am, edited 1 time in total.

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 Post subject: Re: Perpetual power?
PostPosted: Oct Sat 19, 2019 10:00 am 
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 Post subject: Re: Perpetual power?
PostPosted: Oct Sat 19, 2019 12:31 pm 
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That old Die Hard battery was probably a rebranded Energizer battery. They just keep going and going and going.

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 Post subject: Re: Perpetual power?
PostPosted: Oct Sat 19, 2019 3:02 pm 
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Have you by chance started to run the heater in your house as it gets colder, especially if the circuit/battery is near a heater vent?

-Bryan


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 Post subject: Re: Perpetual power?
PostPosted: Oct Sat 19, 2019 3:28 pm 
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Well, one of two things come to mind. Either you've discovered some form of cold fusion power, or the system is drawing power from the other dimension. (See Waldo, by Robert Heinlein). Synopsis on Wikipedia..... jump to Gramps Schneider. also the quote "Magic is loose on the world"

....which it may, in fact, be.

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 Post subject: Re: Perpetual power?
PostPosted: Oct Sat 19, 2019 4:37 pm 
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Long duration intermittent connection?


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 Post subject: Re: Perpetual power?
PostPosted: Oct Sat 19, 2019 9:15 pm 
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Old Rad Lab wrote:
Have you by chance started to run the heater in your house as it gets colder, especially if the circuit/battery is near a heater vent?

-Bryan
Thanks guys for all the ideas:
..So ..Well... as far as I know.. I have not even touched this circuit as it hangs there on the ceiling... BUT
it is sort of 7ft above the baseboard heater on that nearby wall ... so MAYBE ... who knows a little heat from the baseboard heater last week.... woke something up??? I don't know because the heater hasn't been on but once about a week ago or more.

As far as "a possible long intermittent connection" ... remember I haven't moved it or touched it... but who knows ... slight corrosion and electrolysis from operating or something may have slowly changed something... lol

All I know is that darn thing is back to blinking normal ...like a champ.

Maybe it should not have gotten dim as it did there for a few weeks... because MAYBE if it's drawing VERY little current.... then it should go on blinking for the shelf-life of the battery... right? ... But what is the "shelf life" of a used, 9V battery like that with what looks like ... (maybe) a 2011 date code?

I really don't know... it's just doling it's thing now and I haven't a clue.

If you guys have a half-dead 9v around ... try building this using the lowest current that still lets the leds blink for very brief on-cycles but a freq of about twice a second.
Try it.. have fun.
The one in this video is NOT mine but it seems to be blinking with a very similar rate and duty cycle as mine.
https://www.youtube.com/watch?v=u9eAKk6jo2s

https://www.petervis.com/GCSE_Design_an ... asher.html

Remember my transistor are antiques too... Grown Silicon NPN ( TI-904) from the 60s.
So they add a little funky-ness to the mix.

http://www.transparentsound.com/transis ... uments.htm

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 Post subject: Re: Perpetual power?
PostPosted: Oct Sat 19, 2019 9:30 pm 
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Quote:
All I know is that darn thing is back to blinking normal ...like a champ.

Are you absolutely certain it wasn't your eyes that got dim for a few days? None of us are getting any younger you know ...... ;-). 8)

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 Post subject: Re: Perpetual power?
PostPosted: Oct Sun 20, 2019 12:39 am 
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Well, if you didn't test the battery to see if it truly was drained, then it wasn't and your problem lies elsewhere like a bad solder connection or some bad silicon.


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 Post subject: Re: Perpetual power?
PostPosted: Oct Sun 20, 2019 3:59 am 
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Well, Halloween is approaching …
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 Post subject: Re: Perpetual power?
PostPosted: Oct Sun 20, 2019 4:58 am 
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Scott wrote:
Well, if you didn't test the battery to see if it truly was drained, then it wasn't and your problem lies elsewhere like a bad solder connection or some bad silicon.

Very possible.
But I didn't even imagine a need to test the old battery to see if it were truly "drained" ... because it just seemed like it was logical that after a few months the LEDs got dimmer and stopped blinking.... in fact, both seemed to "appear like" they were glowing dimly at the same time.
.. but ( since, technically BOTH leds cannot be "on" at the same time), .... maybe it had somehow broken into high oscillation and perhaps it was actually just switching ultra fast for some reason for that time?

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 Post subject: Re: Perpetual power?
PostPosted: Oct Sun 20, 2019 11:27 pm 
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it could have been a single cell that died early and eventually reversed.
this allowed the device to run again till the next cell drops.
or the voltage drops far enough for it to stop.


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 Post subject: Re: Perpetual power?
PostPosted: Oct Mon 21, 2019 1:06 am 
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Greetings to Pete and the Forum:

My bet is this: Often times, removing a continuous load from a flat battery will allow the battery to "recover" and its output voltage will rise to more normal levels. I am guessing that at low voltage with the LED's barely lit, that the current drain of the circuit was much less than when it is operating normally. Thus, the battery "recovered" enough so that there was again sufficient voltage to operate the circuit normally.

All hypotheses need to be tested before being elevated to the status of a theory, so here's a prediction which will make or break this particular hypothesis: The circuit will operate normally for a much shorter time than previously, after which it will go into the two LED's lit dimly mode. This mode will last longer than the previous time, and the device will then recover normal operation but for a still shorter period. Eventually, the dim mode will be continuous, followed by no light at all as the battery finally dies totally.

Regards,

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 Post subject: Re: Perpetual power?
PostPosted: Oct Mon 21, 2019 2:59 am 
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Jthorusen wrote:
Greetings to Pete and the Forum:

My bet is this: Often times, removing a continuous load from a flat battery will allow the battery to "recover" and its output voltage will rise to more normal levels. I am guessing that at low voltage with the LED's barely lit, that the current drain of the circuit was much less than when it is operating normally. Thus, the battery "recovered" enough so that there was again sufficient voltage to operate the circuit normally.

All hypotheses need to be tested before being elevated to the status of a theory, so here's a prediction which will make or break this particular hypothesis: The circuit will operate normally for a much shorter time than previously, after which it will go into the two LED's lit dimly mode. This mode will last longer than the previous time, and the device will then recover normal operation but for a still shorter period. Eventually, the dim mode will be continuous, followed by no light at all as the battery finally dies totally.

Regards,

That does sound most plausible.
The only weird part for me, is how both LEDs can ever be switched "on" at the same time in a dim state,
unless both transistors were somehow leaking at the same time the same amount.
So this is what led me to think that maybe the "dual dim-state" is some strange oscillation making both LEDs to switch on/off so quickly that they look dim.

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 Post subject: Re: Perpetual power?
PostPosted: Oct Mon 21, 2019 4:17 am 
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A couple of thoughts on the circuit you show.
First, to analyze it there needs to be an unknown, variable resistance between the "+9v" bus and the voltage source to represent the internal source resistance of the dying battery. The battery probably has some unknown time constants & temp sensitivity.
Second, your capacitors may have noticable leakage.
Third, unless some voltage is changing, the caps may as well not be there, a pure dc analysis is needed. There is a meta-stable state (the dual dim), in which nothing is changing, because nothing is changing. An external influence like temperature, or light shining on the LEDs, can push it back into astable mode flipping & flopping.

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 Post subject: Re: Perpetual power?
PostPosted: Oct Mon 21, 2019 5:40 am 
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Put ur volt meter on the battery, then put ur ammeter in series with, it while it's running normally.
Do the same when it's dim, limping along and compare notes.


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 Post subject: Re: Perpetual power?
PostPosted: Oct Mon 21, 2019 7:42 am 
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In my classes I furnished each work station with a Digi-Designer with two
complete blinker circuits assembled on the perf board.

One circuit worked, the other didn't. I had randomly threw in several bad
parts for the students to find, replace and get the bad blinker running. The
could use any of several methods, including meters, curve tracers, transistor
testers, to discover what parts were needed.

I chose the 2N3906 because I had scads of them, mil packed in shielded bags,
in boxes of 100. Also the circuit had to work on the 5 volts furnished by the Digi-Designer.

After this lesson, they knew how to test transistors, leds, capacitors, resistors
bad wiring, and just how devious and treacherous instructors could be. :D
Attachment:
Blinker Project.jpg
Blinker Project.jpg [ 309.67 KiB | Viewed 915 times ]
Attachment:
Digi Doo Doo.jpg
Digi Doo Doo.jpg [ 202.24 KiB | Viewed 909 times ]

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 Post subject: Re: Perpetual power?
PostPosted: Oct Mon 21, 2019 11:26 pm 
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majortom wrote:
Put ur volt meter on the battery, then put ur ammeter in series with, it while it's running normally.
Do the same when it's dim, limping along and compare notes.

I did.
The current voltage is down to +2.78vdc
and
the current current the load is drawing is less than 1 milliamp, at 0.28ma

and now after interrupting it for the readings the blink rate has varied a tad faster and the duty cycle is a bit more brief.

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 Post subject: Re: Perpetual power?
PostPosted: Oct Tue 22, 2019 4:32 am 
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Seen same happen with stuck button garage door opener transmitters. Battery will drain down till the xmitt no longer conducts, at that point the battery slowly regains voltage and BAM! Once necessary potential is reached, transmitter fires and door operates. Voltage drops off & cycle repeats.

Apparently when LEDs are in their "dim glow mode" there isn't enough current being drawn to prevent voltage from rising to point of operating again. Really no different than a flashlight of old going dim, turn off and battery recovers.

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 Post subject: Re: Perpetual power?
PostPosted: Oct Tue 22, 2019 4:39 am 
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35Z5 wrote:
Seen same happen with stuck button garage door opener transmitters. Battery will drain down till the xmitt no longer conducts, at that point the battery slowly regains voltage and BAM! Once necessary potential is reached, transmitter fires and door operates. Voltage drops off & cycle repeats.

Apparently when LEDs are in their "dim glow mode" there isn't enough current being drawn to prevent voltage from rising to point of operating again. Really no different than a flashlight of old going dim, turn off and battery recovers.

yes makes sense anyway at least

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