The Nix Servo Drive is supplied from the Supply and shunt connector, and has separated supply inputs for the logic and the power stage (only required for NIX-5/170-y-z). An internal DC/DC converter provides circuits with appropriate voltages as well as a regulated 5 V output voltage to supply feedback sensors and I/O.
The Nix can be powered from USB for configuration purposes without the need of an external power supply. An internal switch automatically chooses the power source prioritizing the external supply. Please note that motor will not be powered from USB and some functionalities could be limited by the USB port current.
USB Powered Nix
When the Nix is powered from USB, it is not capable of driving a motor, but communications, feedbacks and IOs are fully functional.
There are no critical instructions for disconnecting the Nix. Just some recommendations:
- The board could be hot during < 1 min after disconnection.
- Preferably do not disconnect the supply while having a motor in motion.
- If working with Motion Lab with USB connection, preferably disconnect the drive from the application before disconnecting. This prevents COM port corruption.
Power supply requirements
The choice of a power supply is mainly determined by voltage and current ratings of the power supply. Main requirements of the Nix power supply are:
- The voltage should be the targeted for the motor. This means up to 48 V for the NIX-x/48 and up to 170 V for the NIX-5/170. Make sure that the voltage rating of the power supply does not exceed the voltage rating of the motor, otherwise it could be damaged.
- The current should be the one able to provide the phase peak current of the application. This means up to 10 A for the NIX-5/xx and up to 20 A for the NIX-10/48. Make sure that the current rating for the power supply is at least as high as the motor.
- The voltage and current range can be decreased due to the motor requirements.
Although the logic supply accepts a wide voltage range, a power supply of 24 V and 5 W is recommended for the NIX-5/170-y-z.
Further information on how to dimension a power supply for the Ingenia drives can be found here.
Following are shown different power supply examples:
|Manufacturer||Part Number||Rated Voltage (V)||Rated Current (A)||Image||Description|
|CUI Inc.||VSK-S5-24UA-T||24||230 mA||Enclosed linear power supply for all Nix part numbers logic supply.|
|TDK Lambda||PFE500F48||48||10.5||Switching closed frame power supply recommended for NIX-5/48, 500 W|
|TDK Lambda||PFE1000F48||48||21||Switching closed frame power supply recommended for NIX-10/48, 1000 W|
During power up a short duration high current peak is needed to charge the drive internal DC bus capacitors (see specification page to know the value of the capacitors), this is called inrush current. This current will only be limited by the power supply, the wiring and connectors resistance, the drive reverse polarity protection resistance (~ 65 mΩ) and the bus capacitance equivalent series resistance (ESR ~ 5 mΩ).
Since power supplies have a power-up ramp (or soft start) this typically does not represent a problem at all. However in systems with many axis in parallel or when the DC supply is controlled by a relay, an inrush current limit circuit is strongly suggested, otherwise, the peak can cause unnecessary stress to the power supply and electronics that could reduce its lifespan. There are 2 common ways to solve this.
- Use a passive Inrush Current Limiter (ICL). Which is a negative temperature coefficient (NTC) resistor showing a high resistance at startup that limits the peak and then drops down during operation. This option provides the lowest cost and simplicity but will become hot during operation and reduce system energy efficiency. Choose according to your system current ratings and power supply capacity.
- Use an active precharge relay circuit. By having a current limit resistor between power supply that will limit the inrush and then bypass it with a electromechanical or solid state relay. Some relays include an on-delay function. An alternative is to activate the relay from the driver after power up, by using a macro and a GPO to control the relay.
Power supply connection
Nix logic and power supplies are provided through two different pins, LOGIC_SUP and POW_SUP. Therefore, the logic circuitry and the power stage can be powered from different power supplies.
- Nix versions NIX-10/48 and NIX-15/48 support +10 V to +48 V in both inputs. If logic supply is not connected, the logic is powered from power supply with a bypass diode.
- Nix version NIX-5/170 supports +10 V to +48 V in the LOGIC_SUP input, and +10 V to +170 V in the POW_SUP input. In the 170V version the bypass diode from DC bus is not mounted.
NIX-10/48 and NIX-15/48 double supply
For double supplying the NIX-10/48 and NIX-15/48, logic supply voltage must be higher than or equal to power supply voltage.
Twisted power supply cables are preferred to reduce electromagnetic emissions and increase immunity.
The following picture shows the Nix versions NIX-10/48 and NIX-15/48 supply wiring diagram.
The following picture shows the Nix version NIX-5/170 supply wiring diagram.
Isolated power supplies
For safety reasons, it is important to use power supplies with full galvanic isolation.
Next figure shows a simplified wiring diagram for the NIX-10/48 and NIX-15/48 versions supplied from a battery.
Next figure shows a simplified wiring diagram for the NIX-5/170 supplied from a battery.
Motor braking current
Motor braking can cause reverse current sense and charge the battery.
Always ensure that the battery can accept this charge current which will be within the Nix current ratings.
Connection of multiple drives with the same power supply
When different servo drives are connected to the same power supply, connect them in star topology for reducing cable impedance and common mode coupled noise. That is, connect each drive to the common supply using separate wires for positive and return.
Power supply wiring recommendations
The minimum wire section is determined by the current consumption and the allowed voltage drop across the conductor. It is preferred to use wide section stranded wires to reduce impedance, power losses and ease the assembly. Insulator size should not exceed 3.5 mm (connector pitch). Following table indicates recommended section for the Nix Servo Drive:
|Connection||Minimum wire size||Maximum wire size|
|Stranded wire (preferred)||0.5 mm2 (20 AWG)||1.5 mm2 (16 AWG)|
|Solid wire||0.5 mm2 (20 AWG)||1.5 mm2 (16 AWG)|
For low power applications, it is recommended to use wire ferrules to prevent cable damage or wrong contacts. For higher power applications, direct cable connection is recommended, since it provides lower contact resistance. Due to the connector's size, the maximum allowed ferrule size is 0.5 mm2. Ensure the insulator does not exceed 3.5 mm (connector pitch). Following table indicates recommended wire ferrules for the Nix Servo Drive:
8 mm pin length,
0.5 mm2 (20 AWG)
6 mm pin legth,
0.5 mm2 (20 AWG)
- The distance between the Nix Servo Drive and the power supply should be minimized when possible. Short cables are preferred since they reduce power losses as well as electromagnetic emissions and immunity.
- For best immunity use twisted and shielded 2-wire cables for the DC power supply. This becomes crucial in long cable applications.
- Avoid running supply wires in parallel with other wires for long distances, especially feedback and signal wires.