Encoder

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- richard.rowell
  
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posted
15 years ago

Sat, Apr 4, 2009 4:58 PM

I ripped apart an HP printer and on the back of the carraige that the moved the print heads around was an encoder and a 400 LPI encoder strip. The encoder is labeled H9721P. I can not find a datasheet for it, but there are only 4 pins. I'm guessing one is power, another is ground, then two sensor outputs. I'm curious if the is any way to determine what pins are what?

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It looks like C2 connects pin 2 to pin 4 (if you count the pins from left to right as viewed on the "front" image)

TIA!

- U
- Udo Piechottka
  
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posted
15 years ago

Sat, Apr 4, 2009 9:18 PM

HEDS-9721

-UP

- N
- Nutz
  
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posted
15 years ago

Sun, Apr 5, 2009 3:47 AM

By convention pin 1 often has a square pad. Is your pin 1 really pin 1?

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- a7yvm109gf5d1
  
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posted
15 years ago

Sun, Apr 5, 2009 5:13 AM

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Well, the capacitor that goes to what you think is pin 2 would suggest it's the power pin. The other side of the cap would be ground, now you can beep it out. Or just apply power to the board and measure it. Or find a conventional IC on the board and measure it. So many ways.