Practical Design Considerations of a Low Cost Variable Speed Drive

Variable speed drives (VSD) a.k.a an inverter in the market today mainly use application specific integrated circuits for the construction. These IC´s are capable of generating PWM signals once the required frequencies are input to the device. The commonly used general purpose PIC microcontroller is an effective and a much cheaper substitution to construct the PWM signals required for a VSD. Also, power electronic switching is no easy task when it comes to constructing VSDs. There are many issues that are faced in such circuits such as dirty grounds, cross conduction, etc. Unless these important issues are sufficiently addressed in the development of an inverter, many difficult situations may be faced by the developer. This paper presents development of a low cost VSD and a comprehensive coverage about the practical issues encountered in the development process.