General PCB Motor and Drive Technology FAQ – Infinitum Support Portal

Motor Technology

Who developed this technology? How was it invented?

Ben Schuler, our CEO and Founder, is the inventor of Infinitum Electric’s PCB Stator technology. The original intent behind the company was to capture wasted energy from HVAC systems. While working to reduce the size and cost of the generator in that system, Ben and his team invented the PCB stator technology at the heart of Infinitum’s innovation.

What is a PCB stator?

A PCB (printed circuit board) stator is a unique technology that allows the copper windings of the motor to be etched as coils into a thin, disc-shaped PCB. The PCB stator greatly reduces the size and weight of the motor.

Why is it more efficient?

A traditional motor features a laminated steel core with copper windings, and up to a third of the motor losses are caused by eddy currents in that steel core. When the core and copper windings are replaced by copper traces etched into a PCB, the core losses are eliminated, which provides a higher efficiency motor.

How does the size and form factor compare to conventional motors?

Infinitum’s motors have a geometry commonly referred to as “pancake” or “disc” motors. Aircore EC motors are less than half the volume and weight of conventional AC induction motors and approximately 30% smaller than electrically commutated (EC) motors.

What is an axial flux motor and how does it work?

In an axial flux motor, the magnetic flux travels parallel to the motor shaft, in the axial direction. Traditional AC induction motors are radial flux machines, where the flux travels perpendicular to the motor shaft in the radial direction.

The Infinitum motor is arranged so that the stator and rotor discs are all parallel to each other, and the stator is sandwiched between the rotor discs. As current passes through the coils on the stator PCB, they generate an electromagnetic field which interacts with the magnetic fields from the rotor magnets to generate torque and rotation.

What type of magnets do you use?

Our technology allows the motor to be tailored to the application requirements. We can design your motor with both rare earth and ferrite permanent magnets.

How does the reliability compare to conventional motors?

Third-party reliability tests have shown that the PCB stator is up to 9x more reliable than a conventional copper wire wound stator. Three common failure points in conventional motors are the copper wire windings, insulation between the copper wire and laminated core, and the bearings. In conventional motors, as the stator heats up and cools down, the copper wire windings rub against each other resulting in insulation failure. Additionally, the windings experience increased stress at the end turns which leads to eventual failure.

In contrast, our PCB stator is produced on fully automated equipment without any of the inconsistencies seen on traditional motor windings. The coefficient of thermal expansion of our PCB substrate and the copper is very similar resulting in almost perfect heat dissipation across the entire stator. Thus our design eliminates both the end-turn and insulation failure modes.

What is the efficiency of the motor?

Infinium Aircore EC motors and integrated VFDs meet or exceed AMCA 207 specifications for HVAC applications.

Want to learn more about how we’ve drastically improved motor efficiency with our Aircore EC motors? Download our white paper, “High Efficiency Motors”.

Drive Technology

What is a Variable Frequency Drive (VFD) and why do I need one?

For most applications, supply line power is typically at a fixed voltage. In order to vary the speed and torque of most motors, you need to be able to control the frequency and voltage going into your motor. A Variable Frequency Drive or VFD allows you to control the power going into your motor and more precisely control the performance.

See our YouTube video “What is a VFD?” for more.

How is the motor controlled? What input/output (I/O) and communications are available?

We have the ability to customize the controls to your application. Our Aircore EC motor is controlled via our integrated electronic drive. The drive is a standard 6-pulse drive topology utilizing extremely reliable and ultra-efficient Silicon Carbide (SiC) MOSFET switching devices.

Aircore EC motors offer the same control options as market-leading HVAC variable frequency drives (VFD) and EC motors, making the transitions easy for installers and operators.

Control options include:

Ethernet (Modbus TCP) and RS-485 (Modbus RTU) (BACnet supported in late 2023)
Configurable analog input and output (0-10VDC or 0-20mA)
10VDC reference source for potentiometer control
Configurable digital, 4 in (pull down), 4 out (open collector)
24V courtesy power

What data does the IE motor collect?

Unlike traditional AC Induction motors, Aircore EC motors have sensors integrated into our PCB stator allowing us to measure the health of the motor and the equipment it's driving. The product provides rich data including vibration, motor and drive temperatures, speed, voltage, and current. This information is made available through advanced communication options including a cellular IoT connection, Ethernet (Modbus TCP), and RS-485 (Modbus RTU) with other communication options currently in development.

Our integrated cellular IoT modem also uniquely allows users to transfer this data to our FluxVision IoT cloud dashboard and update firmware more easily.

Can you use the IE motor without a drive?

Our motor requires a drive to operate. The drive is integrated into the motor on our Aircore EC product line; however, we also have the ability to house the drive separately.

Can commercial variable frequency drives (VFD) drive this motor?

Infinitum develops its own inverters to optimize the performance of the motor. The Aircore EC product line features an integrated SiC MOSFET inverter with industry-leading efficiency, communication, and control options.

How do your harmonics compare to conventional VFDs?

We use a standard 6-pulse drive topology and the total harmonic distortion (THD) is similar to competitive commercial and industrial VFDs. Depending on the application requirements, we can implement a variety of harmonic mitigation techniques including AC line reactor/DC link choke, multi-pulse rectifiers, or an active front-end (AFE).