【正文】 一個理想電流源不能被連接到一個理想的開路，因為這會造成正在運行的一個常量，非零電流（從電流源）通過與定義零電流（開放的電路元件）的矛盾。一個理想的電壓源規(guī)定，如果是由開路加載沒有能源（即一個無限阻抗），但方法無限的功率和電流時，負載電阻趨近于零（短路）。 （詳見上的理想運算放大器的文章 在零器。 電阻2R2 RBEzz I VVV ??? , 由于 VD= VBE 中 = ，因此，2R2 RzIV? , R1 的計算方法BZDZS IKI VVVR *1 ? ??? 圖 4補償 電路 這種方法是最有效的齊納二極管，在 V 或以上評級。由于晶體管的 作用 ，發(fā)射極電流 IE 是非常接近等于集電極電流的晶體管集成電路（反過來，是當(dāng)前通過負載）。這些就可以買到這個已經(jīng)在此設(shè)備被稱為電流穩(wěn)壓二極管或恒定電流二極管或限流二極管（ CLD）的案件有關(guān)。盡管如此，在很多情況下，這種電路將提供足夠的性能時指定的電流和負載電阻小。因此，一個理想的電流源可提供無限的 能量將代表無限的能源來源。如果通過一個理想的電流源電流可以指定獨立于任何其他變量的電路，它被稱為一個獨立的電流源。s and Th233。CURRENT SOURCE A current source is an electrical or electronic device that delivers or absorbs electric current. A current source is the dual of a voltage source. The term constantcurrent sink is sometimes used for sources fed from a negative voltage supply. Figure 1 shows a schematic for an ideal current source driving a resistor load. Figure 1 Ideal current sources In circuit theory, an ideal current source is a circuit element where the current through it is independent of the voltage across it. It is a mathematical model, which real devices can only approach in performance. If the current through an ideal current source can be specified independently of any other variable in a circuit, it is called an independent current source. Conversely, if the current through an ideal current source is determined by some other voltage or current in a circuit, it is called a dependent or controlled current source. Symbols for these sources are shown in Figure 2. Figure 2 An independent current source with zero current is identical to an ideal open circuit. For this reason, the internal resistance of an ideal current source is infinite. The voltage across an ideal current source is pletely determined by the circuit it is connected to. When connected to a short circuit, there is zero voltage and thus zero power delivered. When connected to a load resistance, the voltage across the source approaches infinity as the load resistance approaches infinity (an open circuit). Thus, an ideal current source could supply unlimited power forever and so would represent an unlimited source of energy. Connecting an ideal open circuit to an ideal nonzero current source is not valid in circuit analysis as the circuit equation would be paradoxical, ., 5 = 0. No real current source is ideal (no unlimited energy sources exist) and all have a finite internal resistance (none can supply unlimited voltage). However, the internal resistance of a physical current source is effectively modeled in circuit analysis by bining a nonzero resistance in parallel with an ideal current source (the Norton equivalent circuit). Resistor current source The simplest current source consists of a voltage source in series with a resistor. The current available from such a source is given by the ratio of the voltage across the voltage source to the resistance of the resistor. For a nearly i