Ceiling Fan Speed Control Single-phase Motor Speed Control Using Mc9rs08ka2

Freescale Semiconductor, Inc

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Freescale Semiconductor
Application Note
Document Number: AN3471
Rev. 0, 07/2008
Ceiling Fan Speed Control
Single-Phase Motor Speed Control Using MC9RS08KA2
by: Cuauhtemoc Medina
RTAC Americas
1
Introduction
1
2
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.1 Single Phase Induction Motor Control Theory. . . . . 2
2.2 Typical Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3 Proposed Solution and Phase Angle Control . . . . . 3
3
Design Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4
Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.1 Board Configuration. . . . . . . . . . . . . . . . . . . . . . . . . 4
4.2 Rectifier and Transformer . . . . . . . . . . . . . . . . . . . . 5
4.3 Connection from Rectifier to Board . . . . . . . . . . . . . 6
4.4 Pulse Width Modulation (PWM). . . . . . . . . . . . . . . . 6
4.5 Checking the PWM . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.6 Optocouplers (MOC) . . . . . . . . . . . . . . . . . . . . . . . . 9
4.7 Triac and SNUBBER . . . . . . . . . . . . . . . . . . . . . 10
5
Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.1 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.2 Flow Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6
Testing and Validation . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7
Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
8
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
9
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Appendix ABill Of Materials (BOM) . . . . . . . . . . . . . . . . . . . . 18
Appendix BSource Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
This application note introduces a method for controlling
a single-phase AC induction Motor This Motor is widely
used in ceiling fans due to various advantages over other
types of Motors It is low cost, low maintenance, and has
direct connection to the AC power source.
Using the MC9RS08KA2 MCU series combined with
the basic Triac topology is cost-performance solution.
The traditional mechanical speed control of the ceiling
fan can be replaced with this solution avoiding problems
such as non-linearity on speed.
© Freescale Semiconductor, Inc., 2008. All rights reserved.