|How to identify the positive and negative terminals of the light-emitting diode LED energy-saving lamps welding process, often encountered, and this is especially important, the light does not shine on him!
The most commonly used method is the multimeter detection method. Multimeter testing light-emitting diode, you must use the "R × l0k" file. Trapped as light-emitting diode voltage drop of about 3V, while the multimeter is "R × lk" following electrical barrier. Sheet battery is only 1.5V. Below the pipe pressure drop. Either positive, reverse access, a light emitting diode can not be turned on, it can not be detected. "R × 1k" table when the file is connected 9V (or 15V) high-voltage battery, higher than the voltage drop, and so can be used to detect the light-emitting diode. Detection, the two tables document are in contact with the two leads of the light-emitting diodes, such as Biaozhen deflection more than half, at the same time, as one bright spot of light in the light-emitting diodes, light-emitting diode is forward access, this time with a black pen (with battery table connected to the anode) phase is positive; negative battery table with red pen (connected) phase is negative. And then after the swap of the two tables document phase with the light-emitting diode, when reverse access, hands should not move. Forward access or reverse access, hands the deflection are coming to an end or not moving, the light-emitting diode is damaged.
Positive and negative judgment straw hat LED
Straw hat led the positive and negative on the relatively good distinction, or with the easiest way.
Led two massive internal pin we can easily see, we called led bracket, which is relatively large negative bracket, because the negative bracket tray carrying the chip led, small cathode bracket!
So we come to the conclusion is: "Visually, led inside bracket big connection pin is negative bracket small link pin is the cathode
There is a relatively simple method is that if you led a relatively new pin still sound and look directly at the length of the pin, it can be divided out positive pin long "
In fact, there are many methods to detect positive and negative led the cattle method is with a multimeter.
Positive and negative judgment 5050 SMD LED
5050 SMD led is a more commonly used in the LED energy-saving lamps in the lighting industry to chip led, but many users get 5050 SMD led to I do not know how welding because just do not know how to distinguish between the 5050 SMD led the positive and negative today we'll tell you how to distinguish between the 5050 SMD led positive and negative, we have adopted the form of pictures, intuitive to introduce the hope that useful!
Entire 5050 SMD led square, four right angles, missing a corner with a small angle, is that place in a small circle, the right angle without missing angle end with a small missing angle is negative, the other end is positive!