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Optical encoder from ink printer, help understanding

h1tm4nakah

Jan 1, 2016
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Jan 1, 2016
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Hi guys, i've got an optical encoder from an old ink printer. The model is Agilent h9731 ( datasheet http://pdf.datasheetcatalog.com/datasheet2/9/0pql04k9oru8uez14wx9h3d3657y.pdf )
I wired up the Vcc to 5v, GND to GND and ChanA and ChanB to the oscilloscope and everything works fine but the encoder gets warm which i suppose is not good. So ichecked the datasheet and i found out :

Load Capacitance CL 100 pF, 3.2 kΩ pull-up

The pullup resistor is between 5V and Vcc , and the capacitor in in parallel with Vcc and GND ?
 

Bluejets

Oct 5, 2014
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I wouldn't be too concerned at the load capacitance but as the spec sheet says........... supply is 5V dc ........load is pull-up 3.2K ohm.......... i.e. channels A and B (output)....Each one via 3.2K to 5V rail.
Normally means output is open collector.
 

h1tm4nakah

Jan 1, 2016
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Jan 1, 2016
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Thank for the reply, but isnt too strong 3.2k pull up to connect it to a microcontroller? ( like an Arduino).
And having a pull up resistor on the collector shouldnt affect the encoder being warm or not?


I wouldn't be too concerned at the load capacitance but as the spec sheet says........... supply is 5V dc ........load is pull-up 3.2K ohm.......... i.e. channels A and B (output)....Each one via 3.2K to 5V rail.
Normally means output is open collector.
Pin
 
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h1tm4nakah

Jan 1, 2016
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Jan 1, 2016
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The controller doesn't care about the pullup. You should connect the pullup to the micros supply
So i can also use the internal pull up resistor of the Arduino ( 10k ), compared to the suggested 3.2k will only affect the performance but not the current that flow inside the Arduino. Correct me if im wrong, im a newbie :D
 
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