Visible LEDs Application Notes
The features of LED lamps become clear by comparison with tungsten filament incandescent lamps and discharge tubes in their light emitting mechanisms and structures. The following are some qualities of LEDs lamps: Long lifetime – The light emitting phenomenon makes use of the injection light emitted to the P-N junction instead of thermal radiation, therefore, […]
Static Lighting and Dynamic Lighting
An LED can be lit using one of two methods: the static lighting method, in which a constant current is input continually over time, and the dynamic lighting method in which current is fed in continuous ON-OFF pulses. When the ON-OFF intervals are short, dynamic lighting appears to the human eye as static lighting. Figure […]
Precautions for Using LED Lamps
Changes in Characteristics Relating to Temperature (Luminosity, Wavelength, Forward Voltage) The characteristics of an LED lamp change according to the chip temperature (Tj: the temperature of the junction emitting the light). The chip temperature includes both the ambient temperature and the heat emitted by the LED itself. The following text describes typical changes in the […]
Precautions for Lead-Type Radial Taping
LED lamps are sold either loose or tape products. For mounting by hand, loose products are generally used, whereas tape products are required for automatic mounting. Toshiba has radial taping specifications are given in the Tape Specifications. Precautions during Automatic Mounting The following precautions should be observed during automatic mounting. LED lamps have a comparatively […]
Photo Sensor Application Notes
Principle of Operation of Optical Sensors The basic circuit of an optical sensor is shown in Figure 2-2.1(a). The anode of the LED is connected to the power line VCC via resistor RE and the cathode is grounded. Forward current IF is flowing through the LED and is emitting infrared light which is not visible […]
Reliability of LEDs
Longevity Characteristics of LEDs As mentioned earlier, the luminous intensity of LED lamps characteristically declines slowly with use. Select LED lamps according to the level of reliability require in the equipment in which they will be used. Note the following points when requesting LED lamp reliability data from Toshiba, or when using equipment to test […]
Soldering Lead-Type LED Lamps
When soldering lead-type LED lamps, it is important to remember that, since transparent resin has a low softening temperature (glass transition temperature), one must carefully control the soldering temperature. Marktech further recommends that the following precautions be observed when soldering lead-type LED lamps. Soldering Conditions When soldering lead-type LED lamps to the PCB, please follow […]
LED Lamp Selection
LED lamps emit different colors, wavelengths, depending on the materials they are made of. LED lamps based on public standards, for example, LED lamps for specialized traffic signals or automotive stop lamps, frequently use a standardized bulb as the light source. For such applications, select the LED lamp that satisfies the wavelength specifications. Peak and […]
Derating LEDs
Stay informed with the latest technologies, product releases and innovations in the field of Detectors and LED Emitters. Understanding Forward Current vs. Ambient Temperature Figures 1 and 2 show an example in which the current is derated to take temperature into account. Toshiba technical data for an LED lamp usually shows the permissible current values […]
