These solar flowers were being sold off at my local Tesco, a pair of them appeared thanks to my child 😉
They have a small solar panel on top, when they’re exposed to bright light, the flower & leaves move as if they’re being blown in a breeze.
Since one of them didn’t work, I figured I’d tear it down.
The solar cell on the top is similar if not identical to that used on a cheap calculator.
Not much to the control PCB. Just an electrolytic for smoothing the DC coming from the solar cell & a COB IC.
The IC drives this coil of extremely fine wire, glued to the base of the housing. Attached to the green plastic arm should be a magnet – this one has never worked as the magnet is missing. at 50p a piece, a magnet would cost me more than the whole device. So it’s the bin for this one.
I have recently begun to create an archive of all my personal data, and since LTO2 tape drives offer significant capacity (200GB/400GB) per tape, longevity is very high (up to 30 years in archive), & relatively low cost, this is the technology I’ve chosen to use for my long term archiving needs.
Unfortunately, this drive was DOA, due to being dropped in shipping. This drop broke the SCSI LVD connector on the back of the unit, & bent the frame, as can be seen below.
As this drive is unusable, it made for a good teardown candidate.
Here the top cover of the drive has been removed, showing the top of the main logic PCB. The large silver IC in the top corner is the main CPU for the drive. It’s a custom part, but it does have an ARM core.
The two Hitachi ICs are the R/W head interface chipset, while the smaller LSI IC is the SCSI controller.
The tape transport & loading mech can be seen in the lower half of the picture.
Close up of the main logic.
Here the main logic PCB has been removed, showing the tape take up spool. The data cartridges have only one spool to make the size smaller. When the tape is loaded, the drive grabs onto the leader pin at the end of the tape & feeds it onto this spool.
The head assembly is just above the spool.
Bottom of the drive with the cover plate removed. Here the spindle drive motors are visible, both brushless 3-Phase units. Both of these motors are driven by a single controller IC on the other side of the lower logic PCB.
The head is moved up & down the face of the tape by this stepper motor for coarse control, while fine control is provided by a voice coil assembly buried inside the head mount.
The face of the tape R/W head. This unit contains 2 sets of 8 heads, one of which writes to the tape, the other then reads the written data back right after to verify integrity.
The tape cartridge loading motor. I originally thought that this was a standard brushed motor, but it has a ribbon cable emerging, this must be some sort of brushless arrangement.
A replacement drive is on the way, I shall be documenting some more of my archiving efforts & system setup once that unit arrives.
Here’s the teardown of the projector itself! On the right is the info label from the projector, which covers the flex ribbon to the VGA/composite input board below.
This unit is held together with Allen screws, but is easy to get apart.
Here’s the insides of the projector, with just the top cover removed. The main board can be seen under the shielding can, the Micro HDMI connector is on the left & the MicroUSB connection is on the right. The USB connection is solely for charging the battery & provides no data interface to the unit.
On top of the main board is the shield can covering the PicoP Display Engine driver board, this shield was soldered on so no peek inside unfortunately!
The laser module itself is in the front of the unit, the laser assemblies are closest to the camera, on the left is the Direct Doubled Green module, in the centre is the blue diode, and the red diode on the right. Inside the module itself is an arrangement of mirrors & beamsplitters, used to combine the RGB beams from the lasers into a single beam to create any colour in the spectrum.
Here is the module innards revealed, the laser mounts are at the top of the screen, the green module is still mounted on the base casting.
The three dichroic mirrors in the frame do the beam combining, which is then bounced onto the mirror on the far left of the frame, down below the MEMs. From there a final mirror directs the light onto the MEMs scanning mirror before it leaves through the output window.
A trio of photodiodes caters for beam brightness control & colour control, these are located behind the last dichroic turning mirror in the centre of the picture.
This is inside the green laser module, showing the complexity of the device. This laser module is about the size of a UK 5p coin!
And here on the left is the module components labelled.
Here is the main PCB, with the unit’s main ARM CPU on the right, manufactured by ST.
User buttons are along the sides.
Other side of the main board, with ICs that handle video input from the HDMI connector, battery charging via the USB port & various other management.
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