1, for example, a fixed voltage regulator chip Adjustable voltage regulator chip , in its required input voltage range adjustable voltage regulator chip , its output voltage is fixed. Voltage regulation process Adjustable voltage regulator chip : When the input voltage becomes higher, the output voltage will increase, the sampling value of the sampling circuit will also increase, adjustable voltage regulator chip He is compared with the reference voltage, the comparator output voltage is reduced to control the adjustment tube to reduce the output voltage. Description A voltage regulator is a device that stabilizes the output voltage.
2, stable voltage, in the voltage regulator power supply is more used as a fixed voltage regulator chip, in its required input voltage rangeIts output voltage is constant. Models are 78xx of 78 series, 79xx of 79 series, and the last two digits represent the voltage regulator value; LM series of fixed and adjustable voltage regulation.
3, is a voltage regulator power supply chip, its working principle is to maintain the stability of the output voltage by controlling the output current. When the output voltage is reduced, the 7805 will increase the output current to increase the output voltage. When the output voltage rises, the 7805 will reduce the output current to reduce the output voltage. This adjustment allows the 7805 to maintain a stable output voltage within the input voltage fluctuation range.
4, can get a stable voltage; This is the most critical 2 switch chip can reduce power consumption, and can boost the voltage, you can temperature flow, (such as LED lamp special chip) 3 switch chip can reduce heat, reduce volume. If the load is stable, the power supply is stable, regardless of power consumption, heating, of course, you can reduce the resistance. If AC power DC application or rectification filter and other functions.
5, linear power chip Adjustable voltage regulator chip : Linear power chip is a common type of power chip, its working principle is to put the input voltage through...
1, voltage regulator chip, if you want to use this chip to make an adjustable voltage regulator power supply that also has to be designed according to the 7812 chip internal structure circuit to make it, if so, in fact, you are not like to directly use a [LM317 three-end adjustable voltage regulator chip], the chip input 4~37V, output: 25V~37V (adjustable).
Works differently: LM117 Adjustable voltage regulator is very simple to use Adjustable voltage regulator requires only two external resistors to set the output voltage. In addition, its linear adjustment rate and load adjustment rate are better than standard fixed regulators. The LM117 has built-in overload protection, safety zone protection and other protection circuits. Generally, the LM117 does not require an external capacitor adjustable voltage regulator chip unless the connection of the input filter capacitor to the LM117 input is more than 15 cm. Using output capacitors can change transientsRespond.
is different. The lm317 is a three-terminal adjustable positive regulator with output current 5A and output voltage 2V-37V. The lm337 is a three-terminal adjustable negative regulator with an output current of 5A and an output voltage of -2V to -37V.
LM317 is a positive output, and LM337 is a negative output.
Therefore, LM117, LM217, LM317 are negative voltage three-terminal regulators, while LM137, LM237, LM337 are positive voltage three-terminal regulators, and the "1", "2", "3" in front of them are respectivelyRepresents the operating temperature. 1 ranges from -55 to 150, 2 ranges from -25 to 150, and 3 ranges from 0 to 125. The ××117 series is the military supplies type, the ××217 series is the industrial supplies type, and the ××317 series is the civilian supplies type.
The LM337 is a negative voltage model of the LM317 and has a similar relationship with the LM317 to the 7805 and 7905. Output voltage range: -3 -- 40V Output voltage range: -2V -- 37V
The maximum output current of the LM33LM317 is 5A, plus or minus 17V crystalThe peak current of the tube amplifier at full power output reaches 2A, so the power supply composed of LM337 LM317 is not suitable for this power supply. Then the 35W transformer is also small adjustable voltage regulator chip some. On the heating problem, one is the size of the power consumption problem, and the other is the problem of the size of the radiator.