The light-emitting diode, unlike a bulb, works only at respect for polarity. But on the device it is usually not specified. It is possible to define arrangement of conclusions of a light-emitting diode by practical consideration.
Instruction
1. Manufacture the device for check of polarity of light-emitting diodes. For this purpose take a battery compartment on three AA elements, the resistor with a resistance of 1000 Ohms and two probes: red and black. Connect a negative conclusion of a battery compartment directly to the black probe, and positive - via the resistor with the red probe. Place the device in the suitable building. Insert into a battery compartment.
2. To check a light-emitting diode, connect to it probes at first in one polarity, and then if it is not lit, in another. When the diode shines, the black probe is connected to its cathode, and red - to its anode. The resistor in the device is chosen as such that the luminescence was soft, but it was possible to check even the most low-power light-emitting diodes.
3. During the work with light-emitting diodes of emerald, blue, violet and white colors protect them from influence of static electricity.
4. Make a cover for storage of the device manufactured by you. Provide places for separate storage of probes in it. It is necessary in order that they when carrying did not become isolated among themselves. Short circuit will not damage to the device, but if to hold probes closed long, batteries will gradually be discharged via the resistor.
5. Having defined polarity of a light-emitting diode, further do not give on it the return tension. Probability of its exit out of operation at the same time is small, but it is available.
6. If you gained a large number of light-emitting diodes of one type, define polarity of only several of them. Make sure that at all of them the pin-connection diagram is identical. Further for saving of time determine polarity of light-emitting diodes before a vpayka by a form and length of conclusions. But act only this way in case you are precisely sure that all diodes belong to one type.
7. Never use light-emitting diodes without resistors. Even excess of current via such device of all is twice capable to reduce its service life almost a hundred times. Tenfold excess will put it out of action instantly.