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Author Topic: Running an Attiny13a on a saltwater battery :)  (Read 652 times)
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Washington
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Running an attiny13a on a saltwater battery:
Circuit is pretty simple. LED attached from PB3 through a resistor to ground and LED attached to PB4 through a resistor to ground.
code:
Code:
#define F_CPU 128000
#include <avr/io.h>
#include <util/delay.h>
int main(){
        DDRB = 0x18;
        while(1){
                PORTB = 0x8;
                _delay_ms(750);
                PORTB = 0x10;
                _delay_ms(750);
       }
}
Salt battery outputs about 2.4v when fully charged tapering off to about 1v.
The avr works down to about ~1.5v but the LEDS fade out by 1.8v.
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Solid state rectifiers are the only REAL rectifiers.
Resistors for LEDS!

Durham UK
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I love this,

please tell us the timescale of your experiment.

Have you tried a fruit battery or simplest solar panel from  a single LED garden light?

XLP is the future? It's my future!

C.
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Craig Turner, blog: http://gampageek.blogspot.co.uk/ It helps with my learning if I write things down, esp. for others to follow (constructive comments welcomed to improve)

Washington
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I love this,

please tell us the timescale of your experiment.
The LEDS run for about 5 min on the saltwater battery before they are too dim to see. I am sure I could get a longer runtime with more batteries.
Quote
Have you tried a fruit battery or simplest solar panel from  a single LED garden light?
I have not tried a fruit battery but you can find a lemon powered avr on youtube from someone else. I unfortunately do not have access to solar cells.
I used to also have a model wind generator on the roof that produced 1-4v but that stopped working.
[/quote]
XLP is the future? It's my future!

C.
[/quote]
What is XLP?
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Solid state rectifiers are the only REAL rectifiers.
Resistors for LEDS!

Washington
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20 minutes on salt battery!
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Solid state rectifiers are the only REAL rectifiers.
Resistors for LEDS!

Durham UK
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XLP = Xtreme Low Power.

I've just ordered an AVRISP and want to use it explore the various fuse settings on AVR's to minimise power use. That's why I was interested in your experiment. I've got lots of those solar panels from old garden lights. You can pick the lights up at recycling centres in the uk for next to nothing.

I plan to make a garden datalogger that uses only "free power", solar/wind etc..

Also I have read you can harvest RF using a long wire and get power from that by storing charge in capacitors. http://www.mindsetsonline.co.uk/product_info.php?products_id=1009711

AND i'm fairly sure that if sea-water, lemons and potatoes can be turned into batteries then so can animal waste (urine and manure).I have loads of that next door to my garden.http://gizmodo.com/240372/battery-passes-urine-test-running-90-minutes-on-pee is a high-tech version - I want to investigate a garden-type version.

Cheers
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Washington
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XLP = Xtreme Low Power.
Cool.
Quote
I've just ordered an AVRISP and want to use it explore the various fuse settings on AVR's to minimise power use.
I would set the fuse for the 128khz internal oscillator. Its about the lowest power clock and can run down to 1.2v (even though the datasheet say 1.8 ).
Quote
That's why I was interested in your experiment. I've got lots of those solar panels from old garden lights. You can pick the lights up at recycling centres in the uk for next to nothing.
Unfortunately in the USA not near any major city, its not as easy to get ahold of stuff like that.
Quote
I plan to make a garden datalogger that uses only "free power", solar/wind etc..
That is a good idea. Should be no problem with current. The hard part is keeping it running when the sun/wind stops.
Maybe some supercaps?
Quote
Also I have read you can harvest RF using a long wire and get power from that by storing charge in capacitors. http://www.mindsetsonline.co.uk/product_info.php?products_id=1009711
Yes. This does work. Infact I was getting over a volt of output with a longwire and a germanium diode, and a ground/earth connection.
Unfortunately the current was in the low uA because the nearest significant radio station is 20miles/32km away and even that is only 5kw.
Quote
AND i'm fairly sure that if sea-water, lemons and potatoes can be turned into batteries
Certainly. sea-water, lemons and potatos can all be turned into electricity. I find the hardest part is to obtain the zinc electrodes.
FWIW I fish them out of old carbon-zinc batteries but thats a messy and not always successful process.
Quote
then so can animal waste (urine and manure).I have loads of that next door to my garden.http://gizmodo.com/240372/battery-passes-urine-test-running-90-minutes-on-pee is a high-tech version - I want to investigate a garden-type version.
I literally laughed at that smiley-wink

The biggest current draw is usually something external to the MCU. I find the current draw of the MCU is between 150uA to 750uA depending on voltage, clock, processing etc.
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Avoid throwing electronics out as you or someone else might need them for parts or use.
Solid state rectifiers are the only REAL rectifiers.
Resistors for LEDS!

Pittsburgh, PA, USA
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While watching a show about fractals I saw one engineer talk about his idea to first fold up the long wire, which worked, and then making fractal antennae using PCB traces. It worked and that's what cell phones use.

Sneeze, a capacitor that can store actual dangerous amounts of power is pretty cheap and simple to build and at low V probably not so scary-dangerous. Wrap a plastic bucket in foil with one electrode. Fill it with water, maybe a bit of salt. Push a metal rod through the plastic lid and hook the other electrode to that. Yah, it's big compared to a super cap but it's a charge monster too. You could probably do a smaller version with a fast food cup, metallized burger wrapper, rubber band (to hold the wrapper on) and a paper clip though I'm not entirely sure about the wrapper.

Just remember that 5V and enough charge can spot weld or possibly hurt or kill someone. It's all fun and games until then.

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Washington
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Sneeze, a capacitor that can store actual dangerous amounts of power is pretty cheap and simple to build and at low V probably not so scary-dangerous. Wrap a plastic bucket in foil with one electrode. Fill it with water, maybe a bit of salt. Push a metal rod through the plastic lid and hook the other electrode to that. Yah, it's big compared to a super cap but it's a charge monster too. You could probably do a smaller version with a fast food cup, metallized burger wrapper, rubber band (to hold the wrapper on) and a paper clip though I'm not entirely sure about the wrapper.
I think that it would not have that much capacity. Even .1 uf at a few hundred volts is alot but at 5v .1uf is basically nothing.
I am willing to bet such a device is less then 1uf of capacity.
Quote

Just remember that 5V and enough charge can spot weld or possibly hurt or kill someone. It's all fun and games until then.


That maybe true but the "super caps" that I am refering to have a large capacity of around 5000000uf but has very high equivalent series resistance. It can only be charged/discharged at a few hundred mA at best. Such as this: http://search.digikey.com/us/en/products/EEC-S5R5H474/P6980-ND/125085
Notice the 30ohm ESR. 5v / 30 ohms = 166ma. You could not charge or discharge it faster then 166ma. Hardly dangerous.
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Avoid throwing electronics out as you or someone else might need them for parts or use.
Solid state rectifiers are the only REAL rectifiers.
Resistors for LEDS!

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