Abstract
This exploratory study was carried out with the objective to know the optical behavior of light-emitting diode (LED) lamps used and the temperature reached by electronic components that compose the driver (electronic circuit situated inside the body LED lamp) responsible to convert electrical alternating current from power line to direct current to operate the LED devices. Then, two different experiments were carried out with LED lamps. In the first experiment, 131 LED lamps used were chosen randomly and bought from household appliances store (bargain market product) presenting different nominal powers, 8, 10, 12 and 15 watts. All LED lamps were polarized at the power line at 127 V and revealed different optical behaviors, such as: not turn-on; flashing light (as strobe effect); flashing light (as strobe effect) with high intensity (more intense than normal); flashing light (as strobe effect) with low intensity (less intense than normal); fast turnon and turn-off only; and turn-on with low intensity of light (less intense than normal). The hypothesis for these behaviors can be attributed by three different behaviors: in lamps not turn-on, this failure can be attributed for dark spots that are created on the surface of LED device. In these lamps, all LED devices are electrically connected in serial. When a LED is inoperative, the electrical current is interrupted for all LED devices; damage to the electronic components caused by internal high temperature confined inside the lamp body during the operation causing electrical oscillations, as observed from different behaviors from flashing light, flashing light with high intensity, flashing light with low intensity and fast turn-on and turn-off only; swelling of the electrolytic capacitors causing low energy storage and varying the electrical current flow, the electrical current for other electronic components altered the normal optical behavior of the LED lamps. In the second experiment, the temperatures of electronic components located in driver were obtained out of body lamp revealing: from 33 (lowest temperature attributed to inductor) to 52.5ºC (highest temperature attributed to electrolytic capacitor). These temperature values represent the ideal or normal condition of operation for electronic components, but, when they are operating inside the lamp body, the found temperature values increased considerably. This characteristic can be better evidenced by strong color change (caused by accumulative temperature during the elapsed days used) on the printed circuit board used in the driver.
Highlights
Light-emitting diode (LED) is a little semiconductor electronic device mounted with different materials known as p and n types that transforms electrical energy in light[1,2]
This exploratory study was carried out with the objective to know the optical behavior of light-emitting diode (LED) lamps used and the temperature reached by electronic components that compose the driver responsible to convert electrical alternating current from power line to direct current to operate the LED devices
The hypothesis for these behaviors can be attributed by three different behaviors: in lamps not turn-on, this failure can be attributed for dark spots that are created on the surface of LED device
Summary
Light-emitting diode (LED) is a little semiconductor electronic device mounted with different materials known as p and n types that transforms electrical energy in light[1,2]. The elevation of the voltage applied to LED device, it presents resistive (or insulator) electrical behavior; 2. The electrical behavior showed by I (current) vs V (voltage) of LED device (similar as diode) can be divided by two different steps, when it is directly polarized3,4: 1. The recombination of negative and positive charges that are created by different material n and p types inside the LED generates the passage from conduction band to the valence band (Fig. 2), generating the light emission, when the LED is directly polarized[7]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
