![]() ![]() This forms a negative feedback control loop increasing the open-loop gain tends to increase regulation accuracy but reduce stability. Any difference is amplified and used to control the regulation element in such a way as to reduce the voltage error. Zener diode regulators make use of the zener diode's fixed reverse voltage, which can be quite large.įeedback voltage regulators operate by comparing the actual output voltage to some fixed reference voltage. When higher voltage output is needed, a zener diode or series of zener diodes may be employed. Since the forward voltage of a diode is small, this kind of voltage regulator is only suitable for When precise voltage control and efficiency are not important, this design may be fine. Due to the logarithmic shape of diode V-I curves, the voltage across the diode changes only slightly due to changes in current drawn or changes in the input. In an electric power distribution system, voltage regulators may be installed at a substation or along distribution lines so that all customers receive steady voltage independent of how much power is drawn from the line.Įlectronic voltage regulators Block scheme for voltage regulator in an electronic circuitĪ simple voltage/current regulator can be made from a resistor in series with a diode (or series of diodes). In automobile alternators and central power station generator plants, voltage regulators control the output of the plant. Depending on the design, it may be used to regulate one or more AC or DC voltages.Įlectronic voltage regulators are found in devices such as computer power supplies where they stabilize the DC voltages used by the processor and other elements. It may use an electromechanical mechanism, or electronic components. A voltage regulator may use a simple feed-forward design or may include negative feedback. Thus, we can say that the emitter current is the sum of the collector and the base current.System designed to maintain a constant voltage An integrated circuit voltage regulatorĪ voltage regulator is a system designed to automatically maintain a constant voltage. The whole of the emitter current is entered into the base. Thus attract or collect the electrons at the collector. The reversed bias potential of the collector region applies the high attractive force on the electrons reaching collector junction. This base current enters into the collector region. Due to which only a few electrons are combined and remaining constitutes the base current I B. ![]() The base of the NPN transistor is lightly doped. The electrons enter into the P-type material and combine with the holes. When the forward bias is applied across the emitter, the majority charge carriers move towards the base. The emitter of the NPN transistor is heavily doped. The forward biased voltage V EB is small as compared to the reverse bias voltage V CB. ![]() The forward biased is applied across the emitter-base junction, and the reversed biased is applied across the collector-base junction. The circuit diagram of the NPN transistor is shown in the figure below. The collector is always connected to the positive supply, and the base is in negative supply for controlling the ON/OFF states of the transistor. The collector and the base circuit is connected in reverse biased while the emitter and base circuit is connected in forward biased. The emitter is moderately doped, and the collector is heavily doped. The middle section of the NPN transistor is lightly doped, and it is the most important factor of the working of the transistor. The NPN transistor has three terminals, namely emitter, collector and base. ![]() These names are given as per the name of the terminals. The diode on the left side is called an emitter-base diode, and the diodes on the left side are called collector-base diode. The NPN transistor has two diodes connected back to back. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |