Solar animation on the cheap

[sirenwerks]

I was sting at this little bear on a swing toy which I bought my daughter for a buck at the Dollar Store. It rocks back and forth powered by a small solar cell. I was struck by a notion of using this cheap toy to create animation powered by the lighting for the layout. Problem is I am STEM stupid on the practical side and have no idea how these work. Do they use that fancy memory wire?

[jagged ben]

You'd have to give us a link or a picture.  I think the things I've seen use motors.  What's the size of your example?

[narrowminded]

It's an electromagnet in the base and a permanent magnet in a pendulum style device that's very closely balanced so very little force is required to move it.  The electromagnet in the base is slightly offset from the pendulum C/L.  It then swings with the little force that the electromagnet produces with the solar power applied.  You could think of it in a way like the pendulum in a clock driven by a weight but with only the pendulum to drive, nothing else.

[SandyEggoJake]

It's an electromagnet in the base and a permanent magnet in a pendulum

Yep.  I bought and broke open a "rocking Santa" that I got on the cheap, thinking it might make an interesting way to animate a double bucksaw the team... of course I've not done it yet.

[peteski]

It's an electromagnet in the base and a permanent magnet in a pendulum style device that's very closely balanced so very little force is required to move it.  The electromagnet in the base is slightly offset from the pendulum C/L.  It then swings with the little force that the electromagnet produces with the solar power applied.  You could think of it in a way like the pendulum in a clock driven by a weight but with only the pendulum to drive, nothing else.

My GF and also some people at work collect all those little animated solar figurines.  She has me fixing them when they break.

The solar cell provides the power. There is also a capacitor (I assume it is to smooth out the variations in the solar cell voltage (like when it is illuminated with fluorescent lamps which flicker 60 times a second).  The power is fed into a chip which is the driver of the electromagnet (a flat wire coil).  As mentioned, the pendulum part of the figure has a magnet which swings by the electromagnet.  The chip pulses the electromagnet  attracting or repelling the magnet, That causes the pendulum to swing.

These figures are not glued together - they are simply snapped together, so it is easy to take them apart. Just be careful because there are some fine wires in them - they can break really easy.

[sirenwerks]

Yep.  I bought and broke open a "rocking Santa" that I got on the cheap, thinking it might make an interesting way to animate a double bucksaw the team... of course I've not done it yet.

At least I'm not the only one having these geek moments.  But the Dollar Store has them constantly for, wait, here it comes - a dollar; so they seem like a good resource for cheap fun.

[peteski]

If I was to use these for layout animation, the first thing I would get rid of is the solar call. Too unreliable for me. I would build a power supply and power them from one of the layout's power supplies.

[narrowminded]

If I was to use these for layout animation, the first thing I would get rid of is the solar call. Too unreliable for me. I would build a power supply and power them from one of the layout's power supplies.

220, 221, whatever it takes.

[ijzfzzy]

My GF and also some people at work collect all those little animated solar figurines.  She has me fixing them when they break.

The solar cell provides the power. There is also a capacitor (I assume it is to smooth out the variations in the solar cell voltage (like when it is illuminated with fluorescent lamps which flicker 60 times a second).  The power is fed into a chip which is the driver of the electromagnet (a flat wire coil).  As mentioned, the pendulum part of the figure has a magnet which swings by the electromagnet.  The chip pulses the electromagnet  attracting or repelling the magnet, That causes the pendulum to swing.

These figures are not glued together - they are simply snapped together, so it is easy to take them apart. Just be careful because there are some fine wires in them - they can break really easy.

More likely, the capacitor is used by the chip to determine the frequency at which the electromagnet is energized.  Google for 'LM555 timer circuits'.  You'll find circuits similar to the one probably used in these toys.

GDR

[peteski]

More likely, the capacitor is used by the chip to determine the frequency at which the electromagnet is energized.  Google for 'LM555 timer circuits'.  You'll find circuits similar to the one probably used in these toys.

GDR

Maybe, but I think that circuit is a bit more complex than a simple timer.  Different toys have different swing periods and the caps is always the same value.  I actually think that the chip which drives the electromagnet also uses that coil to sense the magnet in the pendulum crossing over the coil, and that determines the cycle for energizing the electromagnet.  Kind of a feedback loop (like BEMF in DCC decoders).  But I could be wrong.

[up1950s]

Will a laser fire up the solar cell ?

Yes it can , somewhat or is that somewatt .

[jagged ben]

Will a laser fire up the solar cell ?

Yes it can , somewhat or is that somewatt .

I still haven't seen the size of this thing, but solar cells output more power when the entire cell is lit up.  If you laser only puts a dot of light on the cell you won't get such good performance as if the whole cell is lit up.

[peteski]

I still haven't seen the size of this thing, but solar cells output more power when the entire cell is lit up.  If you laser only puts a dot of light on the cell you won't get such good performance as if the whole cell is lit up.

It is about 0.5" x 1.25", but it might have 4 individual panels in series (I have not bothered to measure the output voltage, so I'm not sure).  Looks like a thin film of silicon deposited on glass.  IMO, most layouts do not have lighting strong enough to power those doo-dads.  Then some also run nighttime operating sessions which would kill the animation.

[narrowminded]

OK, I couldn't stand it and opened one up.   The voltage cycles on briefly and then off for a longer duration, every couple of seconds or so.  It's only about .7 volts peak when placed under a pretty bright light.  I'm going to guess the capacitor charges up and then the timer, however it works, cycles it on and off.  And that's all I did and all I will do.  And even if I do look at it closer I won't be admitting it in public.

[peteski]

OK, I couldn't stand it and opened one up.   The voltage cycles on briefly and then off for a longer duration, every couple of seconds or so.  It's only about .7 volts peak when placed under a pretty bright light.  I'm going to guess the capacitor charges up and then the timer, however it works, cycles it on and off.  And that's all I did and all I will do.  And even if I do look at it closer I won't be admitting it in public.

0.7V out of the solar panel means it is a single cell.  Or is the 0.7V measured at the coil leads?