led switching power supply is constant voltage or constant current
LED constant voltage power supply is generally called adapter, the output power is relatively large, the internal structure of the photocoupler, there is a cooling fan, the output terminals have a fixed connection wire terminals.
From the LED constant voltage power supply shell marked on the output voltage range, it is different constant voltage value is not the same, but it will mark an output voltage rating, and also marked the positive and negative value of the voltage fluctuation range, generally ± 0.5VDC, for example, a model 12-400W constant voltage power supply, it will be marked with an output of 12 ± 0.5VDC.
LED constant voltage switching power supply is generally allowed under load, not exceeding its rated current value, the output voltage is constant, will not change with the load. Usually used in small power LED module, such as small power LED light strip is more.
Constant current power supply is generally called LED driver board; generally more used in home lighting
Their wiring is almost always zero wire, fire wire and the output of the positive and negative wires or a special plug socket can be. The internal structure between them is very similar, both have power supply chip and high frequency transformer, from the internal structure, constant voltage power supply has photocoupler, and constant current power supply board without photocoupler. The LED constant voltage source refers to the regulated power supply, it can ensure that the output current changes in the case, has been to maintain the voltage constant. From its product shell marked on the output voltage range, it is not the same as the constant voltage power supply, it will be marked a 80V ~ 140V range, its output power is relatively small, is for a certain product supporting the use of the output LED lamp beads in series how much to change, for example, each LED lamp bead is 3V, it can be at least 26 or up to 46 lamp beads.
Constant current source power supply in the allowable load, the output current is constant; will not change with the load changes, usually used in high-power LED products. In the high-grade low-power LED products will also be used in constant current power supply, constant current source in the case of load changes, can automatically adjust their output voltage, making the output current basically remain unchanged as long as LEDs are used. Output current remains basically unchanged as long as the output voltage of LED lamps and lanterns meet the requirements, can be used.
