How to determine the polarity of the light emitting diode?
- Long is positive, short is negative.
- With an ohm table, positive connection, the case where the resistance is small after the reverse connection is: the red pen is connected to the positive pole
- Another way to distinguish is to look at its internal structure. look carefully inside the diode, two pins are connected to two things, a slightly larger like a pot, a small like a cup, imagine the water is from the pot into the cup, just like the current from the positive pole to the negative pole, you can clearly distinguish between them.
- If it is not bright, it may be that the light emitting tube is broken and further measurement is required (note that there are a few models of light emitting diodes that are not bright due to the forward conduction Pressure Drop greater than 1.5 V ).
PCB encapsulation for LED painting
Diode symbol.
In schematic element symbols, the PIN numbers of the diode pins are 1 and 2, but the pad numbers in the diode package are A and K, respectively. As shown in
(A) Diode schematic symbol (B) Diode encapsulation symbol
Light Emitting Diode schematic symbol
The Light Emitting Diode encapsulation symbol is drawn.
