A rotary encoder is an instrument that converts the mechanical energy of rotation into an electrical signal. It is therefore used to calculate the angular position, speed, or direction of rotation of shafts and rotating devices. It can be interfaced and used with Arduino to get the exact digital value of the angular position of any shaft.
Speed of Rotary Encoder
The speed of the rotary encoder is calculated by counting the number of pulses generated in the output. The number of pulses is multiplied by the distance covered by each pulse so that the total distance covered by output pulses is known. This distance is divided by the time taken by output pulses to generate. This gives the speed of a rotary encoder.
Maximum Speed of Rotary Encoder
The maximum speed of the rotary encoder depends on the maximum frequency response of the encoder, the resolution of the rotary encoder, the model of Arduino used, and environmental conditions.
Maximum Frequency Response of Rotary Encoder
The formula for the maximum speed of the rotary encoder in Arduino is given below.
As the formula shows, the maximum speed of a rotary encoder is directly related to its frequency response and inversely related to the pulses generated in each revolution of the rotary encoder. However, the frequency response of the rotary encoder is dependent on the resolution of the rotary encoder. The revolutions per minute multiplied by the resolution of the rotary encoder gives its maximum frequency response.
The resolution of the rotary encoder is explained below.
Resolution of Rotary Encoder
The resolution of the rotary encoder tells about the number of unique positions it has during one revolution. The resolution of the rotary encoder is decided at the time of its manufacturing. Mostly, rotary encoders exist in 10000 Pulses Per Revolution (PPR) resolution. It means that there are 10,000 unique positions of encoder during one revolution. This determines the maximum frequency response of the rotary encoder, and then we can calculate the maximum speed of the rotary encoder.
Manufacturing of Rotary Encoder
The manufacturing of rotary encoders includes their design and construction. For instance, during manufacturing, the resolution of the rotary encoder is increased which means that if unique points during one resolution are increased, the speed of the rotary encoder will increase. Similarly, the operating frequency of the rotary encoder is also determined during manufacturing.
Model of Arduino Used
The maximum speed of the rotary encoder can also vary depending on the model of Arduino used. For example, Arduino UNO has a frequency rating of 16MHz, which means that it can communicate with a rotary encoder at this frequency. However, rotary encoders cannot rotate at MHz frequency. Therefore, Arduino can handle rotation at a few kHz frequencies of a rotary encoder.
Environmental Conditions
Environmental circumstances that include temperature, dryness, and humidity can also affect the maximum speed of the rotary encoder. The temperature rating or rotary encoder is from -40 °C to 120 °C. Therefore, if the rotary encoder gets heated up, it might not rotate at maximum speed. Similarly, a humid environment may not let the rotary encoder rotate freely.
Conclusion
The rotary encoder is a mechanical device that rotates to give electrical signals. Therefore, it can be called an electromechanical device. Its maximum speed is dependent on different factors that include its manufacturing resolution, rated frequency, revolutions per minute, the model of Arduino with which it is interfaced, and environmental conditions.
