Blog

In the family of gearboxes, the planetary speed reducer or gearbox is widely used in transmission systems such as servo motors, stepper motors and DC motors due to its small size, high efficiency, wide deceleration range and high precision. In the premise of ensuring the precision transmission, it is mainly used to reduce the speed, increase torque and reduce the inertia ratio of the loads or motors. Thus, how to choose a right planetary speed reducer or gearbox to fit a motor?

The planetary speed reducer or gearbox is a kind of transmission mechanism. It utilizes the speed transducer of the gearbox to reduce the turnover number of the motor to the required one and obtain a big torque. How does a planetary gearbox work? We can learn more about it from the structure. The main transmission structure of the planetary gearbox is planet gears, sun gear and ring gear.

DC motors are mainly divided into brushless DC motors and brushed DC motors.
Brushed DC motor
DC motor is famous for its good start-up performance and speed performance, in which brushed DC motors use mechanical commutator to make driving simple, see the model diagram shown in Figure 1.
The motor is mainly composed of a stator made of permanent magnetic material, a rotor (armature) wound with a coil winding, a commutator and a brush. As long as the brush A and B at both ends of a certain direct current, the motor commutator will automatically change the direction of the motor rotor magnetic field, so that DC motor rotor will continue to run.

How to choose a right switching power supply? Six tips will give you a guide of selecting a right SMPS power supply: voltage, power, load characteristics...
How to use a switching power supply properly? To use a SMPS power supply properly and in long service life, some suggestions are made for your reference.

Short circuit of the contactor
Possible causes of the fault:

• The contactor works in the environment of damp, dust, steam, or corrosive gases.
• The arc chute damages or falls, load short leads to the contact short of the contactor.
• Incorrect operation of the positive and reverse contactor, as well as unreliable interlocking, make two contactors to pull in at a same time when reversing.

Maintenance method:

1. Improve the working environment and keep clean.
2. Match an arc-extinguishing equipment again.
3. Handle the load short failure.
4. Recheck the contactor's interlocking circuit, change the operation mode.

Contactor is an automatic electromagnetic switch for long-distance frequently connected or disconnected AC and DC main circuit and high-capacity control circuit. The main control object of a contactor is the motor, it can be used to control other loads as well.
According to the current types that through the main contacts, contactor is divided into AC contactor and DC contactor. The structure and working principle of both are basically the same, which mainly consists of three parts, electromagnetic mechanism, contact system and arc-extinguishing equipment. In the electrical control circuit of machine tool, AC contactor is mainly used. This article focuses on the basic structure of the AC contactor.

When switching power supply blows a fuse, when there is no DC output or volatge output is unstable, when switching power supply has poor load capacity, how to do? Click it and then you will know how to deal with these problems as well as some repairing skills.

DC contactor is mainly used for remotely connecting and disconnecting the DC circuit, as well as frequently starting, stopping, reversing and plug braking the DC motors. It's also widely used for connecting and disconnecting the lifting electromagnet, solenoid valve, clutch's magnetic coils. DC contactor has two structure of stereoscopic arrangement and plane arrangement, some products are derived on the basis of AC contactor. Therefore, structure and working principle of the DC contactor are basically the same as that of AC contactor, which mainly consists of three parts, electromagnetic mechanism, contact system and arc-extinguishing equipment.

A contactor is mainly used in a primary loop, which can go through a large current (several hundred to about one thousand Amps). While a relay is used in a secondary circuit to achieve various control functions, which can only go through a small current (several to decades Amps). Functions, contacts opening and closing situation of the two subject are different.

Power line filter is electrical equipment which effectively filters particular frequency point in the power line or the frequency out of the particular frequency point. It is a passive bi-directional network, that is, one end is power supply, and the other end is load. When selecting an EMI power line filter, what should be taken into considerations? Rated voltage, rated current, insertion loss...

What is a power line filter? What does a power line filter do? A power line filter, also called EMI power line filter, is a passive bi-directional network, electrical equipment which effectively filters the particular frequency point in the power line or the frequency out of the particular frequency point. Power line filter is to get a certain frequency power supply signal or the power supply signal after eliminating a certain frequency through connecting power supply filter in power line...

How to select a right solid state relay? When selecting solid state relay(SSR), it should be based on the actual application conditions and SSR performance parameters, and especially take into consideration the overcurrent and overvoltage conditions in the use and the load capacity of SSR, which is helpful to achieve the long life time and high reliability of solid state relays. Then, follow the questions and find the detailed answers to choosing a right  SSR.

What is a solid state relay(SSR)? A solid state relay is a non-contact switch fully composed of solid state electrical-element, which can drive high-current load with a small control signal. It can achieve switching on and off with no contact and no spark due to the switching characteristics of electrical element (i.e. semiconductor components like switch transistor, triac and so on). Solid state relay has such following advantages over electromagnetic relays: high reliability, no contact, no spark, long life, fast switching speed, strong anti-interference ability, and small size.

Solid state relay (SSR) is a non-contact switch composed of solid-state electronic components with high reliability, non-contact, no spark, long life, no noise, no electromagnetic interference, high switching speed. Electromechanical relays (EMR) is a kind of magnetic switch made up of multi-coils, movable elements, contact system etc. and it is easy to drive and widely used in all the areas. Then what are they differences? Which one is better?

What is a servo motor? Servo motor is the motor which controls mechanical components operation in servo system. Servo motor can convert voltage signal to torque and speed, then to drive the control object. The control speed and position accuracy is very high. In auto control system, servo motor can response rapidly as executing component, convert the receiving electrical signal to angular displacement or angular velocity output of motor axis. The main feature is, when signal voltage is zero and no self-rotation, rotation speed will descend at even speed along with the torque increasing. Servo motor has 2 types, DC servo motor and AC servo motor.

Servo driver is a kind of controller used to control the servo motor, which belongs to the servo system. When some problems accur as follow of a servo drive, how we should test and repair? Here are 6 tips  to maintain a servo drive.

Stepper motor is an open loop control element that transforms the electrical pulse signal into angular displacement or linear displacement. When a pulse signal is added to the motor, and the motor turns a step angle. The existence of this linear relationship, and stepper motor with only periodic error and no accumulated error, makes it widely used in various fields. This article describes the application of stepper motor in electronic clocks, industrial robot and packaging machine.

Stepper motors is used in open-loop control, thus it is simple, low cost and can be widely used. However, the open-loop control of the stepper motor cannot avoid the inherent disadvantages of the stepper motor itself, that is, resonance, oscillation, step loss and difficult to achieve high speed. Correspondingly, the closed-loop control of stepper motor can make up these shortcomings, and have the advantages of open-loop drive and brushless DC servo motor.

Sometimes one has to (still) use a dedicated net just for servos but that is old. Different fieldbuses and/or servo drive interfaces may support a partial frame; for example, one may only be able to set a control word which might be position or torque command while some may support a full parameter frame or command set which exposes a plethora of servo parameters and variations between the two extremes. Speed is also a consideration i.e. may only be fast enough to do motion control or fast enough to close a servo torque loops and/or fast enough to incorporate feedback devices e.g. force or range sensors (without wiring directly to the servo drive).

Stepper motors are now widely used in the industrial areas, but from time to time some problems with stepper motors occurs as follows. Aimed to these problems, there are some troubleshooting for your reference.

1. How to control the direction of stepper motor?
2. When stepper motor generates vibration and noise, how to do it?
3. Why the stepper motor doesn’t rotate or move back and forth after it is powered?
4. Why the torque of stepper motor is decreasing with the rise in rotational velocity?
5. Why stepper motor can run normally at low velocity, but can’t start at certain higher velocity with some noise of whistler?
6. How to prevent the power interference of stepper motor?