Posted to News on 21st Oct 2015, 00:00
PCB drive solutions for electric motors
When solutions for starting and running DC electric motors are discussed, the arguments tend to focus on simple DC power supplies with relays and switches at one end of the equation and PLC based motion control systems with master and slave units at the other. In between however is a vast array of PCB motor control options, and in many cases these will provide a much more suitable control solution.
>These can range from simple analogue controllers with a panel knob to vary speed, right up to sophisticated drives with on-board motion control and an array of speed profile functions embedded in a digital signal processor. These PCB-based solutions offer far greater control and protection of the motor than conventional starters, or, where more sophisticated control is required, all the functionality of a traditional inverter or servo amplifier but without the associated cost and complexity. And these PCB solutions enable the engineer to embed the motor control exactly where it is required in the application.
>OEM Automatic offers a full range of PCB motor control solution, from the simplest analogue controller from manufacturers such as Electromen, right up to the most sophisticated motion amplifiers from leaders in the field like Technosoft.
>For example, moving away from a contactor to an open loop DC driver such as the Electromen EM-185 brings basic speed regulation to DC motors plus effective over-current protection. Motor voltage is regulated against supply voltage changes, and there is also load compensation adjustment. The current limit and speed range are readily adjustable with trimmer potentiometers, and the power stage of the device is protected against short circuit and overload. All this in an easy-to-mount package that requires just a 10mm hole in the assembly panel. Already this is a vast improvement on the simple fixed speed, power supply, relays and switch combinations, or indeed basic solid state relay switching.
>Another option might be something like the Electromen EM-241 full bridge DC motor starter, designed to work with DC motors in applications where some special functions are required. The starter has adjustable acceleration and deceleration ramps which enable smoother starts and stops, protecting both the motor from the in-rush currents typical with hard-wired fixed speed starters, and protecting the connected equipment from the mechanical shocks associated with harsh on/off motor control. Further, adjustable current limits protect the motor against over current, and it can also be used as an end stop.
>The EM-241 offers further functions, with two settable speeds which can be useful in positioning applications, while control inputs allow the motor to be started in either forward or reverse direction. Input options include limits, preset speeds and an analogue (0-5V) speed control. A fault output is also provided.
>The full range of Electromen motor controllers is available from OEM Automatic, meeting the needs both of automation subcontractors and of manufacturers of all types of equipment and machinery. They address requirements to add more sophisticated control to existing machinery or to build greater functionality into new machine designs and automation systems.
>Where there is a requirement for more advanced motion control not connected to a PLC system but driven by a PC based embedded solution, OEM Automatic offers a full range of PCB-based control products from Technosoft. These products set themselves apart through the use of innovative MotionChip technology - a dedicated DSP solution for motion control that is embedded in a broad range of intelligent servo drive products.
>Designed to cover both low-volume and high-volume applications, Technosoft's iPOS range of intelligent drives integrate all basic motor control functions and motion control features in a single module. They are based on an innovative design concept that has resulted in cost-effective, compact, modular solutions to the position speed and torque control of rotary or linear brushless, DC brush and step motors.
>Typical of these products is the iPOS4808 MY, which embeds advanced motor control functions, as well as motion control and PLC features, into a plug-in module. For high-end positioning applications, iPOS4808 MY supports dual-loop feedback configuration, as well as on-board interfaces for BiSS/SSI encoders. A faster MotionChip processor, together with larger program and data memory than its predecessors, allow the iPOS4808 MY to offer powerful control algorithms including multiple bi-quad filters for improved motion trajectory with resonance rejection.
>With the development of the iPOS intelligent drives family, Technosoft has also extended the concept of distributed motion control. Now you can split the motion application between the iPOS drives and the EtherCAT or CANopen master. Using Technosoft's motion programming language, you can build complex motion applications locally, on each drive, leaving only the high level of motion application on the EtherCAT or CANopen master, and thus reducing complexity.
>OEM Automatic is also able to offer Technosoft's range of iMOT intelligent motors, which combine an intelligent drive, a motor and a position sensor into a single unit. The result is a cost-effective, compact solution that translates motion commands received through a communication channel into mechanical motion, and is able to execute stand alone complex motion programs, providing an ideal solution for decentralised motion control applications.
