Six basics of servo motors
16. Is it safe to drive the motor with a DC supply voltage greater than the rated voltage?
Normally this is not a problem as long as the motor is running within the set speed and current limits. Since the motor speed is proportional to the motor line voltage, selecting a power supply voltage does not cause overspeed, but a driver failure may occur.
In addition, it must be ensured that the motor meets the minimum inductance requirements of the drive and that the set current limit is less than or equal to the rated current of the motor.
In fact, it is good if you can make the motor run slower in the device you design (less than the rated voltage).
Operating at a lower voltage (and therefore a lower speed) will result in less brush bounce, and less brush/commutator wear, lower current consumption and longer motor life.
On the other hand, if the size and performance requirements of the motor require additional torque and speed, over-driving the motor is also possible, but at the expense of the product's useful life.
17. How do I choose the right power supply for my application?
It is recommended to select a supply voltage value that is 10%-50% higher than the maximum required voltage. This percentage varies with Kt, Ke, and the voltage drop within the system. The current value of the driver should be sufficient to deliver the energy required for the application. Remember that the output voltage of the driver is different from the supply voltage, so the driver output current is also different from the input current. To determine the proper supply current, all power requirements for this application need to be calculated, plus an additional 5%. Calculate according to the I=P/V formula to get the required current value.
It is recommended to select a supply voltage value that is 10%-50% higher than the maximum required voltage. This percentage varies with Kt, Ke, and the voltage drop within the system. The current value of the driver should be sufficient to deliver the energy required for the application. Remember that the output voltage of the driver is different from the supply voltage, so the driver output current is also different from the input current. To determine the proper supply current, all power requirements for this application need to be calculated, plus an additional 5%. Calculate according to the I=P/V formula to get the required current value.
18. What kind of work can I choose for a servo drive?
Different modes do not all exist in all models of drives
19. How is the driver and system grounded?
a. If there is no isolation between the AC power source and the drive DC bus (such as a transformer), do not connect the non-isolated port of the DC bus or the ground of the non-isolated signal to the ground, which may result in equipment damage and personal injury. Because the common voltage of the AC is not to earth, there may be a high voltage between the DC bus ground and the earth.
b. In most servo systems, all common ground and earth are connected together at the signal end. A variety of ground loops generated by grounding are susceptible to noise and generate flow at different reference points.
c. In order to keep the command reference voltage constant, the signal ground of the driver is connected to the signal ground of the controller. It will also be connected to the ground of the external power supply, which will affect the operation of the controller and the drive (eg: 5V power supply for the encoder).
d. Shield grounding is more difficult, there are several ways. The correct shield ground is at the reference potential point inside the circuit. This point depends on whether the noise source and reception are grounded at the same time, or floating. Make sure that the shield is grounded at the same point so that ground current does not flow through the shield.
20. Why can't the reducer match the motor exactly at the standard torque point?
If the maximum continuous torque through the reducer generated by the motor is taken into account, many reduction ratios will far exceed the torque level of the reducer.
If we are designing each reducer to match the full torque, there will be too many combinations of internal gears (larger, more material).
This will make the product price high and violate the "high performance, small size" principle of the product.
21. How to choose to use planetary reducer or spur gear reducer?
Planetary reducers are generally used when high torque is required in a limited space, ie small volume and large torque, and its reliability and life are better than spur gear reducers. Spur gear reducers are used for lower current consumption, low noise and high efficiency low cost applications.
