This decision is usually based on the resolution and accuracy needed as well as the most suitable functional principle (optical/magnetic) and usage temperature range of the encoder types available for the desired motor series.
If a second shaft end is needed, brushless DC motors generally use analog Hall signals for the angle sensors.If needed, encoders are installed downstream of the other add-on components, such as brakes for example.
- Without line driver, line lengths up to 1-2 m are possible with quadrature signals. In individual cases, the function may depend on other parameters, such as the motor PWM and cable installation.
- With line driver and twisted-pair cables, line lengths of up to several tens of meters are conceivable. What matters in this case is the differential evaluation at the end of the line or controller. In addition to this, a connection resistance at the line end may be useful for longer line lengths in order to suppress reflections.
FAULHABER offers encoders based on the optical and magnetic functional principles.
FAULHABER offers encoders with quadrature interface, absolute interface (BiSS), analogue and digital Hall signals.
Yes, quadrature (also RS422); BiSS; UVW for brushless DC motors.
- The resolution of a quadrature encoder (4* pulse count) is the smallest measurable angle.
- As with any measurement system the resolution and the accuracy must not be mixed up. Typically the resolution is expected to be in a range of a factor 10 compared to the accuracy. This would require a 0.09° resolution (4096 increments / 12 bit) for a 0.9° accuracy.
For details check the data sheet or contact our support.
Please note, the accuracy of a position encoder depends on the quality of the coupling between motor and encoder. FAULHABER encoders combined with the motor in our production, so the accuracy as given in the datasheet really applies for the drive system.
Additional protective measures are already incorporated in some encoder products, such as the IE3 and IER3. But generally speaking, the specification limits (e.g. power supply range) indicated in the data sheets must be met. In individual cases, it may be necessary to take additional measures for the customer’s application. What is critical in this respect are primarily voltage peaks on the voltage supply and signal lines, which can lead to a latch-up effect in the sensors and cause their destruction.