Motion System Options for HVAC Gas Valve Actuators

In HVAC systems that provide heat for enclosed spaces, gas and liquid flow must be controlled and metered accurately using sensing and modulating elements such as flow control valves or isolation valves. Some control valves are opened and closed manually at the valve stem, while electronic valves incorporate an actuator to move the stem with control from a motor and drive system. Designers have three motor types to choose from, depending on the application requirements. Here’s a summary of the motion system options:

Tips to Avoid Stepper Motor Resonance Problems 

When an application requires a reliable, low-cost motor with simple operation, stepper motors can be hard to beat. They can be driven step by step without needing an encoder or Hall sensor for rotor position feedback. However, the same straightforward design and driving method that makes stepper motors popular can lead to resonance problems in certain conditions. 

Customized and Reliable Stepper Motors Address HVAC Damper Application Extremes

If you have to regulate HVAC system airflow on a constant basis, you’ll need automatic dampers with electric or pneumatic motors that can be controlled by a thermostat or building automation system. When designing an external mount electric damper actuator for an HVAC system, it’s important to review considerations in order to create the best motor-damper combination.

When evaluating a miniature motor to pair with an actuator, keep in mind that it may need to be customized. Ask yourself the following questions:

Choosing a Motor for Electronic Pipettes

When it comes to dispensing a specific volume of liquid in a lab environment, pipettes are essential. Electronic air displacement pipettes have taken the lead due to the needfor a high level of precision and accuracy required for repeated use over a periodof time. With the improvement of a digital interface for adjusting aspiration or dispensing, electronic pipettes offer a huge advantage and relief from ergonomic methods.

The motor is the key element in the design. When design engineers specify a motor    they must consider factors such as motor power, size and weight, and control electronics. Let’s look at the two most considered motor options - stepper motors and DC motors to help determine the fit for your application.

Bipolar Drives and Unipolar Drives for Stepper Motors: A Comparison

 A stepper motor is a type of brushless DC motor composed of connected coils — called “phases.” These electromechanical devices are generally driven in open loop without a feedback sensor, with current applied on the phases without knowing the rotor position. The rotor moves into alignment by means of the stator’s magnetic flux, generated by the current flowing in the phases. At each pulse, the current can be supplied to the next phase, allowing incremental rotational movements, or steps. There are two methods to supply current in the coil: bipolar and unipolar. This blog post will compare bipolar and unipolar motors.

Did you know: Stepper Disc Magnet Motor Technology Provides Multiple Modes of Operation

Designed and developed in Switzerland, Portescap's Disc Magnet Stepper Motor provide versatility unequaled by any other kind of permanent magnet stepper motor. 

Portescap Motor Technology in Healthcare Simulators

Healthcare simulators are sophisticated training tools for medical professionals that resemble actual patients exhibiting various medical conditions.

When it comes to motion for handheld and miniature medical device designs, a standard electrical mini motor may seem like a good starting point. But while a miniature motor generates rotary movement, applications like medical pipettes or syringes, and mesotherapy devices often move loads linearly instead of rotationally. For these medical tools as well as some industrial devices, engineers must develop their own system to translate rotary motion into linear motion. Here are some of the basics to understand when considering your linear motion options.

Brush DC and Stepper Technologies for Security and Locking Devices

Security systems are an important part of any commercial buildings whether it’s an office or a warehouse. Biometrics is one of the most deployed systems in a wide variety of industries, from government institutions to industrial buildings. A motor plays a vital part in the design of security locks. Portescap offers the best viable solution for these applications with its various technologies.

Portescap's Innovative Dual Motion Can Stack Actuator Solution

Rotary and Linear Motion in One Compact Solution

Some applications require rotary motion, such as ventilators. Others require linear motion, such as medical pipettes or syringes. When it comes to combining a rotary and a linear motion in the same application, designers often need to integrate 2 motorized solutions so they can control both degrees of freedom (rotation and linear) at the same time.

High-Speed Line Actuators

An in-depth discussion on high-speed linear actuators that use disc magnet motor (DMM) technology, and their uses in low-load applications such as sensor movement, positioning a laser beam, pick-and-place of electronic components, movement of XY tables, and other applications. Quiet operation and lower operating and maintenance costs make electric DMM linear actuators a viable option for these high-speed, low-load applications.

In the 80’s, Portescap was mainly involved in the watch industry providing small stepper motors to be used in watches and clocks. Using rare earth magnets, we then designed the first micro motor with a multipolar structure. Such a design avoids additional pole shoes on the rotor to create fewer steps per revolution. Later, Portescap expanded its expertise to include bigger motors for industrial applications [< 100 W].

An expansion valve is a flow-restricting device present in a refrigeration system that causes a pressure drop of the working fluid. The valve needle remains open during steady-state of operation. The size of the opening or the position of the needle is related to pressure and temperature of the evaporator. When set and controlled properly, an expansion valve will keep the evaporator active throughout its operation.  There are two types of electric expansion valve technologies popular in the market place - pulse width modulated valves, and stepper motor driven valves.

Portescap has recently introduced the P532 Series Disc Magnet Step Motor with encoder to deliver best-in-class motor acceleration and power rate and thus outperform the standard Brushless DC motor in a wide range of applications.

Stepper motors typically run at 2,000 RPM or less in an open loop, while brushless motors that can run at much higher speeds are typically used in closed loop applications. In the last few years, trend is to use a stepper motor in closed loop with a torque higher than a brushless motor system, because of its higher pole count. What we are typically looking at is the middle range of revolutions per minute [RPM] as a sweet spot for disc magnet motors. The sweet spot opens up in applications in the few thousand RPM range, where a closed loop disc magnet motor system can be more cost-effective than a brushless solution.

What is a “linear actuator”? It is actually a simple stepper motor with a built-in leadscrew to directly convert rotary motion in form of discrete steps, into linear motion. Achieving linear motion internal to the motor eliminates the cost of designing a separate transmission mechanism in the system.