Solar Dancing Flower

dennis

Member
A friend has one of these solar powered dancing flowers similar to the one in the bottom right of http://www.ecvv.com/product/1127383.html. The solar panel is only 10mm by 21mm and yet the motion is quite energetic even inside in normal daylight on a cloudy autumn day (UK). The motion is interesting and seems chaotic in that the two leaves are linked together but the main stalk seems to have an independant motion.

Suggestions for some pruning to reveal the inner workings have been rejected - so does anyone know how these things work ? Is it a tiny motor or some sort of solenoid ?

As the solar panel is so small I assume the needed current (1 or 2 mA ?) could easily be directly supplied by a Picaxe.
 
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benryves

Senior Member
I'm afraid I'm not sure how they work - my parents recently brought one back from a trip to Malaysia, and requests to dismantle it are likely to receive the same response as the one you've received from your friend - but they are called Flip Flaps, and seem to be going for about a fiver in the UK on a few e-commerce sites (though I haven't seen any with flowers yet, just the leaves).

As they are well balanced and a gentle tap keeps them swaying for a while, one possible technique may be to charge a capacitor using the solar panel. When the capacitor is charged up enough, it is discharged via a solenoid or similar to kick-start the swaying motion.
 
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Rickharris

Senior Member
Having performed the necessary surgery they contain a coil driven by a FLED solar engine circuit see http://www.solarbotics.com /resources/ or http://www.beam-online.com/Robots/Circuits/1381.html or http://faq.solarbotics.net/oscillate.htmlfor details. The flower leaf have neodymium magnets attached so the change in magnetic field makes them move. The coil needs little to drive it as a small magnetic field is required. The FLED could be a picaxe.

The balance is fairly critical as the magnetic push is slight.
 
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dennis

Member
Thanks for the FLED reference I also found this article by Wilf Rigter http://www.solarbotics.net/library/circuits/se_t1_fled.html
which clearly explains the way it works.
Interesting that quite high currents can be obtained even if only for a short time.
I think I will have a go at building one with a coil instead of motor and powered from a Picaxe pin. I assume a series resistor of 250 ohms would be needed to limit the initial inrush as the capacitor charges.
 

Rickharris

Senior Member
Remember you will need to slap a diode across the coil to kill the back EMF It depends on how you go about doing it - a Picaxe will need to be powered itself so you are simply attaching a coil to the output then powering the coil from the picaxe battery.

If you went to the solar cell charging the Cap then the traditional solar engine is better as it requires no outside power.
 
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