Pulse width modulation is one of the most widely used and versatile output techniques available to the embedded designer. This technique is used to generate analog voltage levels and waveforms, implement speed control, and transmit data.
Pulse width modulation consists of a digital signal of fixed period (the low to high transition occurs at a fixed time interval.) The width (W) of the pulse varies between 0 sec and the period (T). The duty cycle (D) of the signal is the ratio of the pulse width to period.
A PWM signal can be generated is several ways using a PIC microcontroller. The most basic method is to write source code than manually toggles at pin. For simple applications this method will suffice. However, more complex applications can not afford the microcontroller bandwidth needed to implement the software toggling method. Microchip microcontrollers equipped with a CCP and ECCP module have a hardware PWM generator build in. The designer simply configures the duty cycle and frequency and these modules take care of the rest.
Document Description
AN847 RC Model Aircraft Motor Control
AN654 PWM, A Software Solution using the 16CXXX Devices
AN594 Using the CCP Modules
AN893 Low-Cost Bidirectional Brushed DC Motor Control Using the PIC16F684
AN538 Using PWM to Generate Analog Output
AN906 Stepper Motor Control Using the PIC16F684
AN901 Using the dsPIC30F for Sensorless BLDC Control
AN857 Brushless DC Motor Control Made Easy
AN900 Controlling 3-Phase AC Induction Motors Using the PIC18F4431
TB081 Soft-Start Controller for Switching Power Supplies
No comments:
Post a Comment