Filters
The pulsations or ripple of the DC voltage can be remove with the proper filter. There are two components used for filtering: a capacitor is used to filter the voltage and an inductor or choke to filter the current.
When a capacitor is used as a filter, it is connected in parallel with the output of power supply, Figure 8-4. Assume that the rectifier or power supply produces an output voltage which has a peak value of 20 volts.
As the voltage rises to its peak value of 20 volts, the capacitor charges to 20 volts also. When the DC waveform tries to drop back toward zero, the line voltage becomes less than the 20 volts the capacitor has been charged to. Therefore, the capacitor discharges back into the line in an effort to keep the voltage from decreasing in value.
When a choke coil is used as a filter, it is connected in series with the output of the rectifier, Figure 8-5. When the current begins to rise from zero toward its peak value, a magnetic field is created around the choke coil. As the current reaches its peak value, the magnetic field does also. They decrease from their peak value back toward zero in the same way. As the magnetic field collapses around the choke coil it induces a current back into the coil. This induced current flows in the same direction as the circuit current. Therefore it aids the circuit current by trying to keep a continuous current flow throughout the circuit.
There are various ways to connect capacitors and chokes into a circuit for filtering. A power supply designed for low power application may use a single capacitor filter. A common filtering arrangement is the “∏”filter. It get its name because it resembles the Greek letter “∏”, Figure8-6.
Power suppliers designed to deliver a large current generally use a choke input filter, Figure 8-7. Choke input means that the choke is connected ahead of the capacitor in reference to the rectifier. This is generally done to keep the surge of current down when the power is turned on.
过滤器
直流电压的波动或纹波可以用适当的滤波器去除。有两个组件：一个用于滤波的电容器是用于过滤的电压和电感或呛滤波器的电流。
当电容器作为一个过滤器，它是接在电源输出，图8-4。假定整流器或电源产生一个输出电压有20伏的峰值。
当电压上升到20伏的峰值，电容充电至20伏特也。当直流波形试图降回零，线电压低于20伏的电容被充电到。因此，该电容放电回线在努力保持电压下降值。
当一个扼流圈作为一个过滤器，它是连接在整流器的输出序列，图8-5。当电流开始上升，从零到峰值，磁场是在扼流圈了。当电流达到峰值，磁场也。他们从他们的峰值减少回零以同样的方式。作为磁场的崩溃在扼流线圈，它诱导电流进入线圈。这种感应的电流在同一方向流动的电流。因此，艾滋病的短路电流，试图在整个电路保持连续的电流。
有各种不同的方法连接电容器和电抗器为电路的滤波。电源的低功耗设计，应用程序可以使用一个单一的电容滤波器。一个常见的过滤装置是“∏”过滤器。它得名是因为它类似于希腊字母“∏”，figure8-6。
电力供应商设计提供大电流一般采用节流输入滤波器，图8-7。扼流圈输入意味着扼流圈连接在电容器中的参考整流器。这通常是保持电流冲击下打开电源时。
的直流电压的脉动或纹波可以除去用适当的过滤器。有用于过滤两部分组成：一个电容器用于过滤的电压和电感器或电抗器进行过滤的电流。
当电容器被用作过滤器，它是连接在与电源的输出端，如图8-4平行。假定该整流器或电源产生一个输出电压，其具有20伏的峰值。
随着电压升高到20伏，电容器充电到20伏也其峰值。当直流波形试图回落到零，线电压小于20伏的电容被充电到。因此，电容器放电回线，以努力保持电压的降低中的值。
当扼流线圈用作过滤器，它被串联连接在所述整流器的输出端，如图8-5所示。当电流开始从零上升到朝向其峰值，一个磁场被扼流线圈周围产生。当电流达到其峰值，磁场的作用也。他们从峰值下降走回零以同样的方式。作为磁场扼流线圈围绕其折叠感应出电流返回到线圈。该感应电流流在相同的方向上的电路的电流。因此，它有助于电路的电流通过试图保持整个电路的连续电流流动。
有多种方法来连接电容器和电抗器转化为一个滤波电路。专为低功耗应用的电源可以使用一个单一的电容滤波。一个常见的过滤安排是“ Π ”过滤器。因为它类似于希腊字母“ Π ” ，图8-2 6它得到它的名字。
旨在提供一个大电流电源供应商一般采用扼流圈输入滤波器，如图8-7 。扼流圈输入装置，该扼流圈被连接前面的电容器在参考整流器的。通常这是保持电流的浪涌下来时，接通电源。