Advantage of low voltage
The low voltage LED are always going to be more advantaged. The energy efficiency of the low voltage LED was high(Low voltage driver and low current consumption.), and along with the voltages increased the energy efficiency was dropping.
For example: the lumens of 1W white led is 100 lm
When VF is 3.0 : 3.0V X 350ma = 1.05W，light effect 100/1.05W = 95.23 lm
When VF is 3.4 : 3.4V X 350ma = 1.19W，light effect 100/1. 19W = 84.03 lm
The upper data structure table is only for your reference, we know that Exercise consumption of energy resources when vf rising.
The Wire specifications of lamp can be divided into the following categories:
BV、BVR、RV：They are all single core cable
BV：BV also single core cable, the wire were relatively hard. , it is not easily deformed.
BVR：The BVR is Stranded wire mixed up and Stranded wire form an indivisible whole. it also call soft wire. example: PVC insulated conductor with copper wire polyethylene solid insulated cord
RV：RV also is soft wire ,the RV differences with the BVR. because the RV was right have more Stranded wire.
BVVB：The BVVB hard casing wire, In each casing will be inserted that three BV wire .
RVV：The RVV soft casing wire, In each casing will be inserted that
three BV wire .
The user set up the multimeter to diode gears. then measuring the good from the bad. the red test pen should be connected to the positive led, and the black one to the negative led. if lit the led is good. Contrary, The led is broken, it can’t be used.
Meanwhile, The screen will be display that led of forward voltage drop(unit as mV).
Red led of forward voltage drop around1.8V
Yellow led of forward voltage drop around2V
Green led of forward voltage drop around2.2V
Blue & white forward voltage drop around3V
LED constant current source
The work processes of LED constant current source were described in detail. Connect with the mains to start, the input voltage start to rise, in the moment we found the current reduced, as the he voltage increasing. the constant current source will be able to deal with output voltage when reaching the enactment standard value of current.
Conversely, The automatic lowering of the output voltage when current increasing
The wire ground connecting of electrical appliance for LED utilizing
On what condition will LED utilizing must be earthed? All appliances must be earthed. Be that the right . let’s analysis the question base on last standard of GB7000.1/IEC60598D.
Class I: The exterior leakage of lamp should be joined together and to the ground .
Class Ⅱ:without grounding
Class Ⅲ: not allowed direct ground connection
Excessive drive current can damage LED . and the constant current source of power supply can avoid the fluctuations of output current due to the fluctuations of input voltage, and maintain the brightness of LED. Make stability the work current was the first requirement for using LED .
Another noteworthy enhancement is startup current, the long-term big startup current above normal limit. must produce a certain damage for LED.
Finally, we need to perfect the current ripple, achieving current sharing. hopefully lasting no more than 30% .
Dimming power supply(0-10V)
The dimming power supply can graduate evenly between the smallest and largest light value.
The Principle and Design of Power Supply of Light Adjustment with Constant Current.
and power conversion efficiency. Control LED light by controlling the bias voltage(as the power supply voltage was increased to output current).
For example:
*the LED is currently turned off when dimming power supply modulated to 0V(the work current was down to 0)
*the work voltage is about to reach 100% when the user turn dimming power supply up to maximum value(10V). the led light significantly increased.
