History
In the end of the Second World War, people proposed a method of motor speed control. At that time, a generator was driven by the original motion, and the generator was adjusted by controlling the excitation of the generator. The output voltage is adjusted to adjust the speed of the driven motor. After the war, with the appearance of the thyristor, the controllable rectification technique is invented, and the voltage is controlled by the conduction time of the thyristor. The emergence of the full-control power tube (GTO, GTR, MOSFET, IGBT, ICGT) can not only control the conduction of the transistor, but also control shutdown, so that the switching frequency is improved, first, the speed control system response speed is very Large improvement, and well solved the current intermittent problem in low speed. After World War II, with the emergence of thyristors technology, some people put forward frequency conversion techniques, thereby achieving speed regulation of AC motors, and the early current type inverter is realized with a crystal gate. The current-type inverter current is large, high harmonics, low efficiency, is not extensive, and the motor is mainly fan motor. With the advancement of science, the total of all types of motor forests, people no longer only have demand for fan motor speed, more demand for various types of motor, and various speed control switches have started to rise Speed speed, variable voltage speed, frequency conversion speed, electromagnetic speed regulation. Due to the non-polar characteristics of the pressure regulation, it is widely used in the civil electronic speed control switch.
Speed Regulation Switch Principle
The speed control switch uses electronic circuit or microprocessing chip to change the number of electric machines, voltage, current, frequency, etc. to control the speed of the motor so that the motor A electronic switch to achieve high use performance.
For the AC motor, the speed regulation method is: inductive speed, tap speed, capacitive speed regulation, cardiosilicon regulation, frequency conversion speed control.
For DC motor, the speed control method is: armature circuit resistance speed, armature voltage regulation, thyristor power supply speed, high power semiconductor device DC motor pulse width Speed, excitation current speed speed.
Motor speed speed is used to use thyristor, which is thyristor, which mainly uses a PWM control principle. That is, let a square wave to control the thyristor, when the square wave is at a high level, the controllable silicon is turned on, and the square wave is at a low position, the controllable silicon is closed. This adjusts the ratio of the high level and the low level (professional, the duty cycle) can change the circuit conduction and the time ratio of the circuit, and when the whole process is turned on, the fan is running at full speed, while the whole process is not turned on The fan stops working. The same can be achieved, half-speed, 1/4 speed, 3/4 speed, etc., theoretically, the possibility of stepless speed can be realized.
Classification
Although the electronic speed switch variety is not much, it is similar to that of the appearance, but it is necessary to seriously identify, and the three classification methods of electronic speed control switches will be briefly introduced.
The electronic speed control switch can be classified according to the operation mode, load power, wiring mode:
1) is divided into: knob speed control switch, button speed switch, speed control Socket switch.
2) According to the load power, the conventional power speed saver switch, medium power speed speed sag, large power speed control switch;
3) divided into: single-line Electronic speed control switch, zero fire line electronic speed control switch.
Application
HW-A-1040 type (DC12V24V voltage universal) governor, working principle: the average current on the load by changing the duty cycle of the output square wave The power changes from 0-100% to change the load, the lighting brightness / motor speed. Using the pulse width modulation (PWM) method, dimming / speed control is achieved, and its advantage is that the energy power of the power supply can be fully utilized, and the efficiency of the circuit is high. For example, when the output is 50%, the pulse width modulation (PWM) circuit output energy power is 50%, that is, almost all energy is converted to the load. When using a common resistance to reduce the speed, it is necessary to obtain a power supply to 50% power. The power supply must provide an output power of more than 71%, which is consumed in the voltage drop and heat dissipation of the resistor. The energy of the large bull is consumed on the resistor, and the remaining is the energy output, and the conversion efficiency is very low. In addition, the HW-A-1040 type speed is hardly existent because of its switching mode, the HW-A-1040 type speed is very large, because the governor is automatically tracking PWM, and the pulse width modulation is used. (PWM) mode, the load can be made almost full power supply voltage during operation, which facilitates overcoming the motor inner coil resistors in the motor to produce a larger torque power. KTS-A10, KTS-A8, KTS-A7, KTS-A6, KTS-A5