In addition, in view of the influence of temperature, the new LED power supply has the function of adapting to the environment. The overall approximate voltage of the luminaire can be obtained by the following formula: Vforward_total = Vforward x Num/String The above formula is relatively simple and can provide the designer with a rough direction, but it is insufficient for the final design of the luminaire. 3 Normal distribution of LED Vf production LED temperature coefficient LED voltage belongs to negative temperature coefficient, which means that the voltage will drop when the temperature rises, on the contrary, the voltage will be relatively high when the temperature is low.
In terms of voltage, the most severe condition will fall when the lamp is cold started.In the design of lamps and lanterns, how to estimate the voltage of the LED is a seemingly simple knowledge that requires attention to many details. The main purpose of lamps is of course to meet the light requirements of the application environment, such as illuminance or color temperature. 2 Actual V-I curve LED production difference LED forward bias voltage will have a certain degree of production difference. Although it is not within its fixed output range, its environmental adaptive function can provide a maximum instantaneous voltage of 275V, which can ensure the stability of the boot.
Method 2: Get the answer from the LED specification sheet and refer to related materials.05A. The impact of production differences on LED voltage is usually less than 10%, which can be seen from the ratio of the maximum value of the reference voltage to the standard value in the LED specification.48 (V) / 3. 3. Take Figure 2 as an example. First of all, the LEDs produced by each factory, even if tested under the same conditions, will have more or less differences in forward bias.190 (V) x 108. Fig.2 = 248. The benefits of this for the design of the lamp will also be explained below.