Pololu QTR-8RC - Manual (Page 6)

4. Distinguishing the QTR-8A from the QTR-8RC
The QTR-8A sensor array has a different output format from the QTR-8RC, so it is important you know which sensor
model you have. What distinguishes one model from another are the components placed on a common PCB. The
pictures below show the two models:
QTR-8A reflectance sensor array.
QTR-8RC reflectance sensor array.
The QTR-8A uses a voltage divider for each sensor’s output while the QTR-8RC uses an RC circuit. This produces
the most visible difference between the two: eight 47k voltage divider resistors (black components with “473” written
on them in yellow) on the QTR-8A are replaced by capacitors (tan components) on the QTR-8RC.
QTR-8A and QTR-8RC Reflectance Sensor Array User's Guide © 2001–2014 Pololu Corporation
4. Distinguishing the QTR-8A from the QTR-8RC Page 6 of 12