I just cant get enough of autodosers
 

This is latest instalment in series.
Possible dosing in a day: 40, 80 and 160ml

http://www.youtube.com/watch?v=GfeAPtJtP_A

that is a great idea. You should do a write up on how to make one. We have one of those automatic air fresheners laying around too!

Nice! I actually have 6 of those automatic air wicks all around the house. Cool little DIY you got there.:proud:

I noticed that, once your battery is low, the motor will become weak which will still depress the air scent nozzle, but enough to just barely spray any out. I threw in 2 rechargeable 2500mAH batteries, and what a big difference in the power of the motor depressing the nozzle. Its shoots 4 feet long mist.

Would that be a problem as the battery gets low? I'm assuming you did run it on the standard battery setup.

Yes, i did run it on pair of 2300 mAh Duracell nimh batteries. Dont know how long would last, didnt manage to test it but i was thinking of connecting spray thing to some 2.5V DC dc power adapter or something (but didnt have one so low at hand). Tried some cellular chargers, led is blinking but motor wont work

Ok, here is short guide how to do it.

First we need to shave off excess plastic from head of pump so wed have to cut less on device.
Next, since output of head is wide and usual air hose wont fit i found some bigger hose which connected output of pump with normal air hose (blue) which goes into aquarium. Some silicon is used to plug eventual holes and you can burn hose a bit for better fit (rhyme!).

http://lh3.ggpht.com/_PEhBCkLpKME/TT...0/IMG_5605.JPG



Now see if head of pump fits in hole in device. Probaby it wont, so take a soldering gun and make it wider. Not TOO wide, it must not have much left-right movement.

http://lh4.ggpht.com/_PEhBCkLpKME/TT...0/IMG_5602.JPG


Cut bottom of bottle so it can fit in device. Carefull not to cut too much or bottle will be too low and moving part wont push head. Cut little by little till it fits. After that connect hose with pump intake , that hose goes into fert container

http://lh6.ggpht.com/_PEhBCkLpKME/TT...0/IMG_5603.JPG

Take some tape or piece of rubber and wrap it around bottle in device so it doesnt flip out when moving part presses head. Test device and see how much is in one squirt, mine was about 1ml.
If 40ml a day is too much for you (which is lowest i got) , you can maybe try to lower bottle so moving part wont fully press head and there will be less liquid in one pump action.
Alternatively, when buying bottle , look for one that have thinest piston in pump (spring is inside). The thinner piston, the less should be in one squirt

That is an awesome idea!

Yep, cell charger current is too low.

I doubt the Airwick has any voltage regulation built-in. But 3.3V is a common max voltage for microcontrollers, so it can probably handle that voltage without a problem; and that opens up a few possibilities. Plus you'd get more motor torque too.

Instead of modifying the doser you could also just dilute your fert mixture. Twice as much water would allow you to keep the 40ml per day but only put in 20ml worth of ferts. Use whatever calculation you need to get the right amount without the hassle of fiddling around with the mechanism.

By the way this sounds great and I'm in the process of whipping up one myself. Great idea!

Yea, im doing that with my two peristaltics which dose ppspro. I wrote a calculator which calculates dosing if we give volume of aqaurium, volume of fert and amount of dosing. I know mix for mine aquarium but people come and beg ;)

Thanks all, this is just a something in return to community ;)

This is somewhat updated version, with bits here and there


Melt a hole in body of bottle and pull trough it hose for fert container

http://lh5.ggpht.com/_PEhBCkLpKME/TT...0/IMG_5609.JPG



Melt edge of plastic bottle sits on and make a rim to make it harder for bottle to slip off...

http://lh4.ggpht.com/_PEhBCkLpKME/TT...0/IMG_5610.JPG


... and close the hatch

http://lh4.ggpht.com/_PEhBCkLpKME/TT...0/IMG_5611.JPG

I have put full batteries on 9 min setting to see how much it can last.

Now all we need is some DC power adapter or something. Can anyone handle this, im bad at electronics?

Yes it can handle 6V, the cellular charger i tried is 5.6V / 380mA . But, like i said motor wont work, it makes some faint buzz but it wont move

I did a 24h test on 9 minutes setting and result is 170ml divided on 160 squirts, that means that one squirt is about 1,0625 ml with this particular bottle.

Odd, I wouldn't have expected that.

But also good, because 5V regulated power supplies with ratings up 1A and higher are fairly common.

Whats the difference between regulated and unregulated power supply? And what is switching power supply?

Unregulated power supply

The most frequently encountered species is the "wall wart". Here we see one grazing in its natural habitat:

http://www.horrorseek.com/home/hallo...l_WallWart.jpg

This contains a transformer to convert 120VAC to lower voltage AC, a bridge rectifier to convert that to massively fluctuating DC, and a capacitor to smooth out and average the DC to some usable value.

The actual voltage out depends on the load it's powering. Around it's intended load, it will be around the voltage marked on the case, more or less. Load it too much and the voltage drops, load it very lightly (or not at all) and the voltage can go 30% or more higher than its rated output.

Consequently, equipment powered by this often has a regulator, which steps the power from the "wall wart" down to an even lower, but much more constant voltage. See below.

Regulated Power Supply

There are two main species: linear and switching.

Linear power supplies reduce a higher and possibly fluctuating DC voltage to a lower and constant DC voltage. This is what I mentioned above. It functions by turning all the excess voltage to heat, which must be dissipated, and isn't very efficient - especially if the voltage differential is large. But they can be very simple and cheap, even consisting of just a single electronic component; like this one, which is about 0.3" wide:

http://www.reuk.co.uk/OtherImages/lm...lator-chip.jpg

Switching power supplies are a much more complicated beast, with many subspecies. Depending on design, they may be powered from AC or DC.

From a non-electronics standpoint, think of trying to maintain a constant speed on a bicycle. When you go too slow, you pedal; if you reach or exceed your desired speed, you stop pedaling and flywheel.

The switching power supply performs a similar feat tens of thousands of times a second by closing an electronic switch between the input and output to "pedal" and raise the output voltage, or closing it and letting the "flywheel" run to let the output voltage drop.

Switching power supplies can be very efficient, especially compared to linear ones. They produce little heat and waste little electricity.

They're everywhere. There's a big fancy one powering your computer. Many consumer electronic devices use external ones, and they typically look like this:

http://www.b2b-power-supply.com/rima...-40-watt-B.jpg

Though some of the newer ones have advanced in miniaturization to the point where they resemble unregulated wall warts.

That's the basics. Let me know if you need more specific details on anything.

Tnx man :proud:, now im off to do some educated buy :biggrin: