This is revision A of the Encoder1 Module.

Encoder1 Module (Revision A)

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1. Introduction
2. Hardware
- 2.1 Circuit Schematic
- 2.2 Printed Circuit Board
3. Issues

1. Introduction

The Encoder1 module is a low cost quadrature encoder that works with a paper disk of black and white stripes.

2. Hardware

The hardware consists of a circuit schematic and a printed circuit board.

2.1 Circuit Schematic

The schematic for the Encoder1 Module is shown below:

This schematic shows 5 sensors, but at most 3 should be installed. A pair of sensor should be installed at U1 and U4 or U2 and U3. If you need an index pulse, install a sensor at U5.

The parts list kept in a separate file -- encoder1.ptl.

2.2 Printed Circuit Board

The printed circuit board files are listed below:

encoder1_back.png: The solder side layer.
encoder1_front.png: The component side layer.
encoder1_artwork.png: The artwork layer.
encoder1.gbl: The RS-274X "Gerber" back (solder side) layer.
encoder1.gtl: The RS-274X "Gerber" top (component side) layer.
encoder1.gal: The RS-274X "Gerber" artwork layer.
encoder1.drl: The "Excellon" NC drill file.
encoder1.tol: The tool rack file.

3. Issues

The following fabrication issues came up:

There only needs to be one pull up and current limit resistor per sensor. Since there is a maximum of three sensors, only 6 resistors are needed.
All of the senors need to be on the same side!
Think about trimming the sensors in halve.
The lead spacing for the sensors neads to be increased.
Index sensor is pretty close to screw holes. move it in a little.