In a switching cycle; when 0
Ton
In the braking state, id is a negative value VT2 to play a role. This happens when the speed needs to be reduced during electric operation. At this time, first reduce the control voltage to narrow the positive pulse of Ug1 and widen the negative pulse, thereby reducing the average armature voltage Ud. However, due to the electromechanical inertia, the speed and the back electromotive force E are too late to change, resulting in the situation of the E port Ud, which quickly reverses the current id, VD2 is cut off, and VT2 starts to conduct.
Principle of DC pwn converterThe DC converter transforms a DC power supply into another DC power supply with different output characteristics. The DC converter here specifically refers to a DC-DC converter.
Pulse Width Modulation (PWM) is the abbreviation of "Pulse Width Modulation" in English, and pulse width modulation for short. It is a very effective technology that uses the digital output of a microprocessor to control analog circuits. It is widely used in measurement, Communication to many fields of power control and conversion
The so-called pulse width actually refers to the width of the pulse. For example: we put a basin of water, and it takes 1 minute to fill it up without stopping, but in order to control the full time, I need to turn it on and turn off every second. The ratio of the time between opening and closing can be regarded as the duty cycle of the pulse. If the opening time is longer, the corresponding closing time will be shortened (opening and closing must be completed once per second, which is equivalent to the frequency of the pulse). The full time can be adjusted in this way (equivalent to controlling the output). In this way, the output is adjusted by adjusting the on and off time (pulse width), which is pulse width modulation.
FundamentalThe control method is to control the on and off of the switching devices of the inverter circuit, so that a series of pulses of equal amplitude are obtained at the output end, and these pulses are used to replace the sine wave or the required waveform. That is, multiple pulses are generated in the half cycle of the output waveform, so that the equivalent voltage of each pulse is a sinusoidal waveform, and the obtained output is smooth and has less low-order harmonics.
Advantages: The signals from the processor to the controlled system are in digital form, without digital-to-analog conversion. Keeping the signal in digital form minimizes the effect of noise. Noise can only affect digital signals when it is strong enough to change logic 1 to logic 0 or change logic 0 to logic 1.
Related Links What is the principle of DC PWM converter DC PWM converter
1.2mm Wire To Board Connectors
ShenZhen Antenk Electronics Co,Ltd , https://www.antenkelec.com