What is the meaning of PWM control of variable speed vacuum pump and variable speed vacuum pump?

What is the meaning of PWM control of variable speed vacuum pump and variable speed vacuum pump?

That is to say, the speed of the pump motor (brushless motor) can be changed by the PWM method, thereby changing the parameters such as the flow rate of the pump. This kind of speed-regulating vacuum pump, speed-regulating air pump and speed-regulating water pump are high-end products of micro-pumps, especially the products with FG speed feedback signal are rare, which are high-end products, which are more convenient for automation, widely It is used for various instruments and equipment with intelligent requirements. To fully use the function of the variable speed air pump, a control circuit is required, the PWM signal is output to control the pump, and the FG signal fed back by the pump can be received to realize closed loop control. The details of the PWM control are as follows:

PWM is the abbreviation of "Pulse Width Modulation" in English, "Pulse Width Modulation", referred to as pulse width modulation. It is a very effective technique for controlling analog circuits by using the digital output of a microprocessor, and is widely used in many fields such as measurement analysis, power control and conversion. An analog control method that modulates the bias of the gate or base of the transistor according to the change of the corresponding load to realize the change of the on-time of the output transistor or transistor of the regulated power supply. This way, the output voltage of the power supply can work. The condition remains constant as the condition changes.

PWM is a method of digitally encoding analog signal levels. With the use of a high resolution counter, the duty cycle of the square wave is modulated to encode the level of a particular analog signal. The PWM signal is still digital because at any given time, the full-scale DC supply is either fully (ON) or completely OFF. The voltage or current source is applied to the analog load in a repeating pulse sequence of ON or OFF. When the DC power is applied to the load, the power supply is disconnected when it is disconnected. Any analog value can be encoded using PWM as long as the bandwidth is sufficient.

For VML series speed regulating vacuum pump and FML series speed regulating air pump, the high level of PWM signal should be between 2~5V, the low level should be between 0~0.8V, and the frequency should be between 15KHz~25KHz.

For VLK series and FLC series speed control pumps, the high level of the PWM signal should be between 2 and 5V, the low level should be between 0 and 0.8V, and the frequency should be between 20KHz and 30KHz.

If you do not use the FG feedback signal and PWM function of the speed control pump, it can still operate normally and be used as a normal micro pump. However, compared with ordinary micro-pumps, it has extremely low interference, long life, and self-protection functions such as overheat protection and overload protection.