It's an old radio

E - Teardown

Folder: Electronics
Looking at the innards of electronic devices.
The heads

The heads

23 Jan 2011 84
Coil + parking position bumper

Coil + parking position bumper

23 Jan 2011 98
The heads

The heads

23 Jan 2011 87
Harddisk hub motor

Harddisk hub motor

23 Jan 2011 105
It is indeed a BLDC motor. The coils are Y-wound.
Harddisk hub motor

Harddisk hub motor

23 Jan 2011 117
It is indeed a BLDC motor. The coils are Y-wound. The left pad goes to the center point N, the remaining are the 3 phases U,V,W. Single-coil-resistance is about 1.6 Ohm. The disk's PCB contains a Hitachi HA13645 driver. Unfortunately I just can't find a datasheet for that. From what I've read so far, driving these with back EMF detection on the un-driven coils could be quite difficult. scholar.lib.vt.edu/theses/available/etd-09152003-171904/u... www.atmel.com/dyn/general/tech_doc.asp?doc_id=10416
Harddisk - stuff thrown away

Harddisk - stuff thrown away

23 Jan 2011 79
Coin inserted

Coin inserted

31 Dec 2011 67
Piggy Bank sensor module

Piggy Bank sensor module

31 Dec 2011 59
Counting Piggy Bank

Counting Piggy Bank

31 Dec 2011 63
Piggy Bank lid

Piggy Bank lid

31 Dec 2011 69
Counting Piggy Bank

Counting Piggy Bank

31 Dec 2011 81
Piggy Bank innards

Piggy Bank innards

31 Dec 2011 77
Senosor module

Senosor module

31 Dec 2011 57
Sensor module

Sensor module

31 Dec 2011 67
The hidden brain

The hidden brain

31 Dec 2011 68
LCD zebra strip

LCD zebra strip

31 Dec 2011 71
Sensor opened up

Sensor opened up

31 Dec 2011 80
It turns out that it is just a bunch of contacts that get bridged depending on the diameter of the coin.
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31 Dec 2011 70
322 items in total