This preview shows page 1. Sign up to view the full content.
Unformatted text preview: r doing other things. The CCP module
only requires that the developer configure the parameters of the module. Configuring the module includes
setting the frequency and duty cycle registers. 2010 Microchip Technology Inc. The ECCP module (short for Enhanced Capture
Compare and PWM) provides the same functionality as
the CCP module with the added capability of driving a
full or half-bridge circuit. The ECCP module also has
auto-shutdown capability and programmable dead
Note: Microchip Application Note AN893 gives a
detailed explanation of configuring the
ECCP module for driving a BDC motor.
The application note also includes
firmware and drive circuit examples. FEEDBACK MECHANISMS
Though the speed of a BDC motor is generally proportional to duty cycle, no motor is ideal. Heat, commutator
wear and load all affect the speed of a motor. In
systems where precise speed control is required, it is a
good idea to include some sort of feedback mechanism
in the system.
Speed feedback is implemented in one of two ways.
The first involves the use of a speed sensor of some
kind. The second uses the BEMF...
View Full Document
- Winter '10