October 2012

Power Consumption with Feedback Devices

By Nathan Mathiot, HEIDENHAIN Product Specialist

Nathan Mathiot
HEIDENHAIN Product Specialist

When evaluating the total power usage for a machine, the feedback system is often overlooked on power consumption. HEIDENHAIN encoders require a stabilized DC voltage as a power supply. The power supply specification shown in the HEIDENHAIN catalogs is for the voltage levels measured at the encoder. The end user has the ability to monitor and adjust the voltage going to the encoder through the sensor lines.

To determine the amount of voltage drop from the length of cable chosen, use the equation listed below.

The encoder chosen for this example is an LC 183 with a 6 mm diameter cable and 10 meter armored cable. The current consumption of the encoder is 150 mA. The cross section of the power lines can be found in the chart shown below and in any HEIDENHAIN encoder brochure.

The voltage drop is found to be 0.7 V based on the information provided above. Once the voltage drop has been determined, all the parameters for the encoder and subsequent electronics can be calculated such as voltage at the encoder, current requirements, power consumption of the encoder and power to be provided to subsequent electronics. This calculation needs to be taken in consideration on cables lengths longer than 3 meters and make sure to pay close attention to the specifications in the HEIDENHAIN catalogs specific to each encoder.