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# What is this thing? A counter? A clock? Answered

So I was taking apart something, and found this odd-looking thing I just cant figure out what it is though. I tried looking up a part number, but it doesnt have one, it just says 2222 8403 on the back. It has 6 pins, and a dial on the front that can turn from 0 - 9. And sorry about the camera, its not a very good one.

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## Discussions

It's a BCD switch - 2 of the pins will be common, and the others will be connected as binary outputs i.e.
0 = 0000
1 = 0001
2 = 0010
3 = 0011
4 = 0100
5 = 0101
6 = 0110
7 = 0111
8 = 1000
9 = 1001
Where '0' is not connected to the common, '1' is.
'2222' is the manufacturers reference and it was made in week 3 of 1984.

Is there a data sheet somewhere for it or something?

The pinouts will be very easy to work out using a resistance meter or simple LED and resistor circuit, like the one HERE.
Set the dial to '0' and 2 of the pins will be connected together. These are the common pins.
If you set the dial to '1', the additional pin connected to common is the 4th column in my table above. Set to "2" you'll get the 3rd column. Set to '4' you'll get the 2nd column and set to '8' you'll get the 4th. They will probably be in order.
It is possible that they are connected the other way around, so '0' is '1111' i.e. all connected.