1. What is alternating current?

 

The magnitude and direction of current change with time is called alternating current. The electricity in our daily life is alternating current.

 

Abbreviation: AC The following is the waveform of single-phase AC voltage

 

2. What is direct current?

 

The magnitude of the DC current is generally stable. There is no change in direction. The DC power supply is generally a stable current. For example: battery power or AC power after rectification and filtering.

 

Abbreviation: DC The following are the waveforms of several DC voltages

 

3. What is a DC speed controller (DC brushed motor speed controller, DC motor speed controller, DC motor speed controller)

 

An electronic device that can drive and control the speed of a DC brushed motor is called a DC speed regulator.

 

DC speed regulators are divided into: silicon controlled chopper type (SCR) and pulse width modulation type (PWM)

 

1. Thyristor type DC speed regulator

 

Advantages: low cost, easy to achieve high voltage, high power, good anti-interference performance, good impact resistance, low requirements for the use environment, etc.

 

Disadvantages: low speed control accuracy and high noise

 

Scope of application: suitable for continuous operation of mechanical equipment with large starting and operating torques, such as machine tools, drilling machines, grinders, continuous operation production equipment and equipment that do not require high precision.

 

2. What is pulse width modulation (PWM)

 

Advantages: high speed regulation accuracy, low motor noise, high efficiency, wide speed regulation range, small motor running sparks (can extend the service life of the motor), etc.

 

Disadvantages: poor impact resistance, large heat generation, large interference, large volume, not suitable for high power, high requirements for the use environment, etc.

 

Fourth, what is a servo controller (or servo control system) -------- for short: servo

 

"Servo" is defined as the meaning of "servant". Usually means: accurate positioning or speed operation according to the received instructions.

 

The servo controller has high speed control accuracy, powerful functions, complete protection measures, etc. The servo controller must have speed closed loop (speed generator or encoder feedback) and current closed loop control.

 

Servo controller is divided into: DC brush servo, DC brushless servo and AC servo

 

DC brushed servo: refers to a system device that can drive and control the speed of a brushed motor (the motor must have a tachogenerator or encoder on the rear shaft), called: DC brushed servo.

 

DC brushless servo: refers to a system device that can drive and control the speed of a brushless motor (the motor must have an encoder on the rear shaft), called: DC brushless servo.

 

Note: The system is generally sold together with the matching brushless motor when it is sold, mainly to ensure the control accuracy.

 

AC Servo: The difference between AC servo and DC brushless servo is that the internal output waveform control method is different. The motor controlled is the same as the DC brushless DC motor. At present, there are few domestic productions. Application: suitable for high control accuracy, Equipment with precise positioning and fast dynamic response, such as CNC machine tools, engraving machines, manipulators, etc.

 

Five, what is an AC governor

 

AC speed governor refers to an electronic device that can control the speed of an AC motor. AC speed governors are divided into single-phase and three-phase speed governors. Single-phase AC speed governors: (refer to single-phase AC 220V), and simple Type and single-phase inverter speed regulation.

 

Three-phase AC speed regulator (refers to the power input is three-phase AC 380V), currently basically all three-phase inverter speed control.

 

Sixth, what is a brushless DC motor controller

 

Brushless DC motor speed controller referred to as: brushless controller,

 

A. The brushless DC motor is a special and special three-phase AC motor, but its operation must be driven by a special controller, because the controller controls the motor through the principle of DC pulse width modulation (PWM) Speed, so it is called a brushless DC motor speed controller (brushless controller).

 

B. Brushless DC motor speed controllers are divided into two types: the controller with position feedback (Hall feedback) and the controller without position feedback (Hall feedback). The controller without position feedback is because of its control The motor has low requirements, large control errors, and low price of the whole set. Currently, it is mainly used in household appliances, such as household refrigerators, air conditioners and electric bicycles.

 

Seven, what is an AC voltage regulating module

 

AC voltage regulation-to put it simply, it is: voltage regulation and control of AC power to achieve different output voltage requirements.

 

Module-it means small size.

 

8. What is the rated input voltage

 

That is: the specified requirements for the voltage index of the product input.

 

Nine, what is the rated output voltage

 

That is: the regulation of the output voltage range at the output end of the product.

 

10. What is the rated output current

 

That is: the current output at the output of the product is limited.

 

11. What is the rated input voltage frequency

 

That is: when the product power input terminal is AC power supply, the number of times the specified sine wave changes in a unit time (unit time: times/second), the AC frequency used in our country is 50Hz/sec, and the AC frequency in some countries is 60Hz/sec.

 

12. What is pulse width modulation (PWM)

 

The circuit that fixes the pulse frequency and then adjusts the pulse width is called pulse width modulation (PWM)

 

13. What is thyristor chopper

 

That is: the AC sine wave is chopped through the unidirectional conduction characteristic of the thyristor to obtain the required output voltage.

 

Note: This method can only adopt the form of thyristor chopping when the power supply adopts AC input.

 

14. What is short circuit protection

 

Short circuit protection: using our product to explain it is: the output current of the governor does not flow through the normal load, but through the connection of the abnormal load, which causes the output current to be far greater than the rated current of the drive. At this time, the internal current detection of the governor The circuit is judged as "overcurrent" and protected, and the governor stops output. So as to effectively protect the drive from damage.

 

15. What is overcurrent protection (also can be called: overcurrent protection, overload protection)

 

Overcurrent protection: The internal circuit of the governor is equipped with an output current detection circuit. This circuit will detect the change of the output current in real time. When the circuit detects that the output current is greater than the set current value, it will be judged as an abnormal output current. Blocking the output terminal of the governor to stop the output or force the output current to be limited to the set value, thereby effectively protecting the governor from damage caused by overcurrent, and at the same time protecting the motor from overload or abnormal current caused by its own Damage.

 

16. What is voltage feedback

 

It means that in the loop of the speed control system, a certain proportion of the voltage value is collected in the output stage and introduced to the input stage in the form of negative feedback, and then real-time monitoring, comparison, and correction of the output stage voltage are carried out with the given value of the input stage. This ensures that the voltage of the output stage follows and stabilizes within the range of the given value of the input stage. This method is called-voltage negative feedback.

 

17. What is current feedback

 

It means that in the loop of the speed control system, a current signal of a certain proportion is collected at the output stage and introduced into the input stage in the form of positive feedback, and then superimposed with the signal of the input stage to promote the voltage and current of the output stage to increase. This method is called-current positive feedback

 

18. What is soft start

 

It means that the speed of the motor reaches the set value through a slow acceleration process from the beginning of the start. This process is called soft start. The process of soft start takes time "seconds" as the unit.

 

19. What is a soft stop

 

It refers to the process of the motor's speed slowly decelerating from the set value to the "0" speed. This process is called soft stop, and the process of soft stop takes the time "second" as the unit.

 

Twenty, what is torque compensation

 

It means that when the motor is running (especially at low speed), the dedicated circuit inside the governor can detect the size of the motor load torque in real time, and then automatically adjust the compensation value according to the torque "compensation potentiometer" setting value.

 

21. What is open loop control

 

The so-called open loop means that the input and output do not form a closed loop. In theory, this control method has low control accuracy and poor stability. (For our drive, closed-loop control generally refers to closed-loop speed)

 

The speed accuracy of the general speed open loop governor is not high (up to 1% speed accuracy), and it can only be applied to occasions with low requirements.

 

22. What is closed-loop control (also called "closed-loop feedback control") and speed feedback (speed feedback)

 

Closed loop: the output feedback (collection) is superimposed with the input value, compared and corrected with the given amount, and then the output value is adjusted according to the error value to make the output value more stable within the given range.

 

Rotation speed feedback means that a tachogenerator or encoder is installed on the execution motor as a feedback element for closed-loop control. It can detect the error signal between the execution motor speed and a given expected value in real time, and then feedback the error signal to the system for dynamic correction processing .

 

The advantages of this closed-loop method are: this control method has the advantages of high precision, stable control, fast dynamic response, good followability, and constant torque.

 

23. What is constant power speed regulation?

 

Constant power means that the power remains unchanged, and the speed and torque are inversely proportional; such as: stepper motor

 

24. What is constant torque speed regulation?

 

Constant torque means that the torque does not change, and the speed is proportional to the power.

 

Sichuan Renyi Electric Co., Ltd. is registered under the name of Ren Yi, a senior technician for substation maintenance, and uses scientific research, knowledge innovation, publicity, promotion, and teaching that the temperature of electrical contacts (connectors) is lower than the temperature of its conductors (wires). The theory and technology of "thermal electrical contacts" produces and sells electrical equipment with registered trademarks that do not overheat electrical contacts (joints). Patented products are integrated.