Are led light driver power supply and switching power supply the same?
Are led light driver power supply and switching power supply the same? For the input voltage of AC220V LED lamp driver power supply, its input AC220V voltage first rectified, filtered into DC high voltage, and then by the special constant current driver IC (such as HV9910) will be the DC high voltage into a constant current output. We know that the LED lamp beads is a non-linear components, in the lamp beads after conduction, the lamp beads on both sides of the forward voltage as long as there is a small fluctuation, the flow of the lamp beads of the forward current will be a large change, so the LED lamp beads are generally used in a constant-current drive, so that regardless of whether the driver power supply to drive a lamp beads or dozens of lamps, the current flowing through the lamp beads is a constant.
For the input voltage of AC220V switching power supply, its input stage circuit is also the first AC220V rectification, filtering into DC high voltage, but after the use of special voltage regulator IC will be the DC high voltage to the required stable voltage. As the output voltage of the switching power supply is constant, the output current varies with the load, so this power supply can not be directly connected to the LED lamp beads, otherwise the lamp beads will be damaged due to excessive current flow.
LED driver is also a switching power supply
1, designed as an electronic transformer type voltage output in the form of 3.2V, 6.4V.9.6V, 12.8V ..... , but the most generally does not exceed 25.6V, because more than this number of When the LED is turned on, the possibility of burning out the last conductive LED will occur instantly due to the bad one to one nature of the product. And this voltage is not constant, but With the change of the load and change, in order to achieve the purpose of constant current.
2, its output current is constant, the ideal circuit is no matter how the characteristic curve of the LED changes, the current of the drive power supply remains unchanged. But limited to component precision, or There will be a small amount of change, and this change is also an important parameter to determine whether the driver circuit is excellent, LED on and voltage function is a non-linear "three" relationship, so maintain a constant current. Relationship, so it is very important to maintain a constant current.
3, its start is soft start. Due to the consistency of the LED is very poor, and in the on-time activity of the internal PN junction instantaneous changes, so the LED driver is generally designed For soft start, to avoid this defect.
So the LED driver is a constant-current mode of operation, the electronic transformer is fixed, the two are different.
