The DynaMotor™ Integrated Motor/Drive

•How it Works

•Basic Description

•Torque and Speed Adjustment

•Self-Contained Closed-Loop Drive

•No Extra Reversing Electronics

•Low RFI and GFCI

•High Reliability

The DynaMotor™ Integrated Motor/Drive

— What It Is and How It Works —

The DynaMotor™ is a revolutionary variable-speed motor-drive that produces high torque at low speed, high starting torque while providing low Radio Frequency Interference (RFI) and Ground Fault Circuit Interrupter (GFCI) operation.

DynaMotors™ has developed the most fundamental motor-drive improvement in fifty years to enhance performance and reduce costs. Its’ elegantly simple design eliminates components and complexities inherent in older AC and DC motor-drives to provide high reliability, better performance, and low acquisition and installation cost.

Basic Description

The DynaMotor™ looks like an ordinary AC or DC motor. It is the same shape and size and is made from the same mechanical parts; laminations, windings, shaft, end-bell, bearings and housing. The difference is that the DynaMotor™ uses optically controlled solid-state switches embedded in its rotor windings. Opening and closing these switches controls the current, and thus the torque, right where it is being produced. The result is enhanced performance in a package that is more than a motor but a self contained variable-speed drive.

The DynaMotor™ is constructed somewhat like a DC motor, or universal motor used in hand drills, etc., with a pair of opposed salient poles whose copper winding are connected directly to the two legs of a single-phase or three phase line.

The rotor is similar to universal and DC motors, consisting of slotted steel laminations stacked on a shaft.

Slotted Armature

Copper wire is wound in opposite slots and the two ends of each coil are connected by a solid-state switch, such as a transistor. In contrast, universal and DC motors have each coil connected to copper bars in a commutator that receives external power through carbon brushes.

Switch Open

When the stator poles are connected to an AC line, a resultant magnetic field varies with the line current and the flux passes directly through the rotor inducing a voltage in each rotor coil. When the solid-state switch is closed, current flows through the coil, producing flux, torque and rotation.

Coil Closed with Rotation

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Torque and Speed Adjustment

When the switch is open, current cannot flow and no torque or rotation is produced by the coil. Closing the switch for a longer period produces more torque and increases the speed. Thus, the motor’s torque and speed can be adjusted as desired by controlling how long (over what rotational angle) the switches are open.

Time/angle switches closed vs. speed

Each switch is actuated by a photo-detector as it rotates past a stationary illuminated infrared light-emitting diode (LED). An array of LED’s mounted on the motor end-bell can be turned on for varying amounts of time to adjust the motor’s speed.

The DynaMotor™

As shown above, the stationary and rotating switches and associated electronic components can be installed outside the main motor compartment to protect them from heat and dirt and to permit easy replacement. This is accomplished by bringing leads from the rotor coils out through the bearing via slots in the motor shaft.

Since there are multiple coils on the rotor that can be energized simultaneously and controlled individually, continuous smooth torque can be produced.

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Self-Contained Closed-Loop Drive

A simple internal optical speed sensor provides speed feedback thus making the DynaMotor™ a self-contained, closed-loop drive system. The speed can be controlled manually with a potentiometer or keypad or automatically by transducer or serial link, etc.

No Extra Reversing Electronics

The direction of rotation can be reversed easily for a motor of any size without contactors or an additional set of power electronics by merely turning on LED’s on the opposite side of each stator pole.

LED Quadrant vs. Direction

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Low RFI and GFCI

DynaMotors™ unique use of optically controlled non-contact solid-state switches eliminates traditional motor-drive pulse width modulation that generates significant amounts of RFI and ground currents that prevent operation on GFCI protected circuits.

CLICK GRAPHS TO ENLARGE

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High Reliability

The simplicity of the DynaMotor™ technology reduces the number of components required by older technology motor-drives and results in not only increased performance as described above but increased reliability and lower acquisition and installation cost.

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