122-28176 Parallax Inc, 122-28176 Datasheet - Page 2

• Manufacturer Part Number: 122-28176
• Description: GUIDE STUDENT PROCESS CONTROL
• Manufacturer: Parallax Inc

Specifications of 122-28176

• Accessory Type: Manual
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Propeller Education (PE) Kit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

Part Substitution from Authorship to Publication
A part substitution was made during editing and formatting of the text from one which was tested
and used by the author to the QRB1114. The IR phototransistor in the QRB1114 has a much
higher sensitivity than the device used in the development of the material resulting in saturation
of the phototransistor very easily.
Recommendations
To adjust the parts and activities to compensate for this increased sensitivity, the following is
recommended, though other values may be tested to achieve desired results:
Specific Modifications to Chapter 4 Activities
Activity #1
1. Page 86, Figure 4-2: Modify R
• Increase the value of the IR LED resistor by a factor of 10, from 100 Ω to 1 kΩ. This
• Reduce the size of all values of R
will greatly reduce the emitted IR and therefore the reflected IR to be sensed by the
phototransistor. This resistor is labeled R
greatly reduce the sensitivity of the photo transistor. This resistor is labeled R
throughout Chapter 4.
© Parallax, Inc. • Errata for Process Control v1.0 (#28176)
o 1 MΩ
o 100 kΩ
o 10 kΩ
6
to 1 kΩ and R
100 kΩ
10 kΩ
1 kΩ
C
for the phototransistor by a factor of 10. This will
6
C
in Figure 4-2, page 86.
to 1 kΩ as shown below.
•
Figure 0-1
Opto-Reflective
Switch Monitoring
v1.0 5/22/06
•
Page 2 of 4
C