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Electronic Circuit

NFO Sinus
 Unique technology

The unique feature of NFO Sinus is that the voltage is switched in the transistors so that the inverter provides an output in the form of a pure sine wave. This eliminates all electromagnetic interference. NFO Sinus is the only frequency inverter on the market that uses this technology.

Conventional frequency inverters, based on PWM technology, chop the voltage into short pulses, which generates electromagnetic interference (both conducted and airborne).

Sinus Switch

The switch connection in each motor phase consists of two transistors, a coil, and two capacitors, as well as logic and regulators for control.

The transistors switch so that the current in the coil is triangular, they turn on at zero current (so-called soft switching) and off at full current. The capacitors act as buffers to ensure a smooth current to the motor.

A regulator in the switch connection calculates the timing of the transistors so that the voltage to the motor corresponds to its sinusoidal set value.

Sinus switch

"The unique technology has advantages from many different aspects"

No Need for Shielded Cables
NFO Sinus meets the EMC directive without requiring filters and shielded cables, making it suitable for various environments, including industrial, agricultural, residential, and medical settings.

Existing unshielded cabling can be utilized, reducing the need for additional work or costly EMC-rated installation accessories such as screw connections and switches.

Comparison with PWM - All PWM inverters must be installed with EMC rated shielded cabling and all installation accessories must be EMC rated.
No complicated installation requirements
NFO Sinus has no specific EMC restrictions for installation, streamlining the installation process without the need for specialized EMC knowledge.

Comparison with PWM - There are strict requirements on how the cabling is done and the installer often has to have special EMC competence.
No restrictions in distance between motor and inverter
With NFO Sinus, you can have a long distance between the motor and the inverter - several hundred meters. The inverter can  be placed centrally in a service-friendly location - exactly where you want it. The only limiting factor is the resistance of the cable.

Comparison with PWM - The maximum distance between inverter and motor varies between different PWM inverters but is often limited to a few tens of meters.


No electromagnetic interference
NFO Sinus produces a pure sine output voltage, ensuring an interference-free operation with no electromagnetic disturbances or irritating switch sounds.

Comparison with PWM - In PWM inverters, the voltage is chopped in short pulses, which gives rise to electromagnetic interference (both wire and air-borne).
No annoying switch sounds
NFO Sinus produces no switch noise in the engine and environment, thus ensuring a quiet and pleasant environment for both humans and animals.

Comparison with PWM - When the current is switched in the transistors, an irritated high-frequency sound occurs in the motor.


No bearing currents
NFO Sinus does not give rise to any bearing currents and the motor thus has a longer service life.

Comparison with PWM - PWM technology creates electrical discharges that strike through the motor bearings. The sparks that then form punch holes in the ball bearings. Motor teamclean therefore wears out quickly – sometimes in just a few months.
No ground currents
No ground currents are generated, and you thus avoid both interference with technical equipment and discomfort for animals. NFO Sinus does not produce earth currents and therefore earth fault circuit breakers for both people- and fire protection can be used.
Comparison with PWM - PWM inverters have such high ground currents that their installation becomes challenging in setups with earth-fault circuit breakers, and it becomes entirely unfeasible with earth-fault circuit breakers designed for personal protection. It's important to note that the ground current increases when using shielded cables, which are always necessary when installing PWM inverters!
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