Što je rad princip linearno regulirano napajanje opskrba
Accord to the working state of the regulating tube, we often divide the regulated power supply into two categories: linear regulated power supply and switching regulated power supply. In addition, there a a small power supply that uses a Zener tube.
The linear regulated power supply mentioned here referers to the DC regulated power supply in which the regulator tube works in a linear state. The adjustment tube works a a linear state, which can be shvaćen in in this way: RW (vidi the analysis below) is continu variable, that is, linear. It is different in the switching power supply. The Switching tube (in the switching power supply, we general call the adjusting tube a switching tube) works in two states: on and off: on - the resistance is very small; off - the resistance is very small; off -the resistance is very small big. A tube work in an on-off state is this in a linear state.
The linear regulated power supply is a type of DC regulated power supply that was used earlier. The karakteristike the the linear regulated DC power supply are: the output voltage is lower than the input voltage; the response speed is fast, the out ripple is small; the noise generated by the work is low; the efficiency is low (the LDO that is often seen now appears to solve the efficiency problem) ; Large heat generation (special high-power power supply), which indirekt increases thermal noise to the sustav.
Working principle: Let's first use the following figure to illustrate the principle of linear relawated power supply to regullate voltage.
The varijabla otpornik RW i the opterećenje otpornik RL form a napon razdjelnik krug, i izlaz napon voltage is:
Uo=Ui×RL/(RW plus RL), so by adjust the the size of RW, the output voltage can be changed. Please note that in this formula, if we only look at the value change of the adjustable resistor RW, the out of Uo is not linear, but if we look at RW and RL together, it is linear. Also note that our figure does not draw the lead-out of RW to the left, but to the right. Although there is no difference from the formula, the drawing on the right just reflects the concepts of "sampling" and "feedback"--most of the the actual power supplies work in the mode of sampling and feedback Below, the feedforward method is Rarely used, or if it is used, it Is Only An Auxiliar Method.
Let's continue: If we use a triode or polje effect tranzistor to replace the variable resistor in the figure, and control the resistance value of this "varistor" by detecting the output voltage, so that the output voltage remains constant, so so we can The Purpose of voltage stabilization is achieved. This triode or field effect tube is used to adjust the voltage output, so it is called an podešavanje cijev.
Since the regulator tube is connected in series between the power supply and the load, it is called a series regulated power supply. Correspondingly, there is also a shunt-type regulated power supply, which is to adjust the output voltage by connecting a regulator tube in parallel with the load. The typical reference voltage regulator TL431 is a shunt-type voltage regulator. The so-called parallel connection means that like the voltage regulator tube in Figure 2, the "stability" of the emitter voltage of the attenuating amplifier tube is ensured by shunting. Maybe this figure does not let you see that it is "parallel connection", but On closer inspection, it is indeed so. However, everyone should pay attention here: the voltage regulator tube here works in its nonlinear region, so if you think it is a power supply, it is also a nonlinear power supply. In order to make it easier for everyone to understand, let's look back at a reasonably suitable picture until we can understand it concisely.
