PWM Signal Controls in DC Motors

Pelonis Technologies, Inc. (PTI) is a leading global manufacturer of brushless DC fans, axial AC fans, and motors serving a wide array of industries including the aerospace, defense, medical, heating and air conditions, appliances, and automotive sectors.

With more than 25 years of experience in developing and manufacturing new and custom products, PTI has built a strong specialization in highly technical fan solutions for the original equipment manufacturing (OEM) field and developed state-of-the-art, fully ISO certified production facilities.

As is often required in highly specialized applications, our expertise includes complex electronics required to make fans run in specific ways. One such method is pulse width modulation (PWM) signal controls for fan speed. 

What are PWM Signal Controls?

Our Pulse Width Modulation Signal (PPWM) Controls control the speed of a fan by applying dc-fan.jpga PWM signal, which has a frequency ranging from 30 Hz to 30 KHz.

PPWM Controls take incoming electricity and convert it into what is called a “Duty Cycle” by creating square waves. Square waves occur when the voltage of electricity instantaneously spikes from a prescribed minimum level to a prescribed maximum level and remains there for a predetermined amount of time. Together, the peak (maximum voltage) and trough (minimum voltage) of a PWM signal comprise the Duty Cycle.

The percentage of a Duty Cycle during which maximum voltage is important and ultimately determines the fan speed. If the square wave is at its maximum voltage for 10% of the Duty Cycle, it is a 10% Duty Cycle; if it is at its maximum voltage for 50%, it is a 50% Duty Cycle, and so on. According to prewritten equations, our PPWM controls adjust a fan’s speed based on the Duty Cycle percentage — the higher the percentage, the faster the fan speed.

Why PWM Controls?

PWM control remains a popular method of fan speed control for a number of reasons.

One reason is that motors, DC motors in particular, are very responsive to PWM. They adjust their speed with little lag time after receiving a PWM signal. Another factor is that PWM signals themselves are very fast, especially when few or no computations are required.

Finally, motor responsiveness and innate PWM speed combine to make PWM Controllers extremely efficient, especially in applications that are highly temperature sensitive and require temperature changes to be made quickly.

Controls at PTI

PTI has worked diligently over the years to master all aspects of fan and motor design and production. This includes a deep knowledge of fan speed signal controls, PWM and others. 

To learn more about pulse width modulation signal controls, as well as other types of signal controls, download our eBook, “How to Select a Cooling Fan,” for free today.

How to select a cooling fan eBook