Motion control refers to the ability to vary speed and sense of rotation of an electric motor, in a controlled and predictable manner. mSemicon has developed a set of motion control products aimed at adding motion control features to applications which until now have had to operate with motors that do not have this versatility, particularly applications that operate at ordinary domestic line voltages where the resistance to innovation has been most acute.
mSemicon would welcome the opportunity to discuss the eventual application of its technology in specific OEM products.
The mere possibility of varying speed in a motorised application, regardless of how it is achieved, is a major factor in achieving power requirement reductions, and therefore energy savings. However when accompanied by the use of an efficient motion control technology, the reductions are even more dramatic.
Asynchronous Motor Control
Three-phase induction motor control is a very mature technology with minimal motor tooling costs, but with exceptional performance. Speed can be varied, with full torque, from the rest state. Reversal is easy, with no external parts, such as relays, required. It can be absolutely silent. Unlike directly connected single-phase motors, the power supplied can be made to match the load, so that no power is wasted. Best of all, application specific intelligence can easily be implemented within the drive that causes specific actions to be taken automatically whenever certain events take place. For example, in case of an overload, the speed could automatically be reduced, or direction reversed, or whatever is appropriate for the application.
mSemicon has developed a set of three-phase inverters that work off single-phase supplies. The electronics convert the single-phase to three-phase, at variable frequency and voltage. This technology has been used in industry for decades, in automation in particular, but has until now been relatively expensive for higher volume applications. mSemicon has adapted this technology for these markets, by making it cost competitive.
Permanent Magnet Motor Control
Three phase permanent magnet motors can be controlled in a manner very similar to three phase induction motors. The inverters that run these motors are physically very similar, with the main difference being in their ability (and indeed necessity) to sense rotor position, sometimes in a sensorless fashion, ie without specific parts.
The main difference between the brushless motor, rated at line voltage, and a three phase motor is that the motor is generally a little more efficient for the same size, but also a little more expensive.
Universal Motor Control
Universal motors are very prevalent in the domestic appliance market, being quite inexpensive for what they offer. In general, given a particular load condition, the speed can be varied on these motors by varying the input voltage. The most cost effective way of doing this is by using a triac, an electronic component whose operation causes the line voltage to be blocked for a controlled part of the line cycle.
mSemicon has developed a set of very inexpensive (single direction) phase controlled triac circuits for use with appliance applications.
Electromagnetic Compatibility (EMC)
All mSemicon motion control products are designed for compliance with applicable EMC regulations. One of the most significant EMC regulations, EN61000, stipulates the need for power factor correction (PFC) for higher power devices. EN61000 limits allowable harmonic current emissions for network connected European electric devices. mSemicon products satisfy these regulations, along with other EMC regulations.
Since advanced drive solutions can improve the sound quality of many applications, noise testing can often be performed to quantify improvements. mSemicon uses state-of-the-art facilities for this purpose.
mSemicon’s products use the latest control technology, including components such as microcontrollers and DSPs, FPGAs, and CPLDs.