LED strip light-Beam angle-Dimming-LED PCB
LED strip light
What do the numbers mean (5050, 3528, 3014, etc.)? These number correlate to the size of the SMD LED chip sizes in millimeters.
An LED Strip Light (also known as an LED tape or ribbon light) is a flexible circuit board populated by surface mounted light-emitting diodes (SMD LEDs) and other components that usually comes with an adhesive backing. Traditionally, strip lights had been used solely in accent lighting, backlighting, task lighting, and decorative lighting applications. Increased luminous efficacy and higher-power SMDs have allowed LED strip lights to be used in applications such as high brightness task lighting, fluorescent and halogen lighting fixture replacements, indirect lighting applications, Ultra Violet inspection during manufacturing processes, set and costume design, and even growing plants.
Typical SMD LEDs are rated as having a 120° beam angle, directed "up", ie. perpendicular to the mounting surface. 'Side View' or 'Edge Emitter' SMDs are designed is such that light is emitted parallel to the adhering surface (ie, 90 deg difference to typical tape design). These allow the construction of LED strips which wash surfaces within less space or accent edge profiles such as signage.
LED strips are not dimmable in the conventional sense. Attempting to vary the brightness of the LEDs by changing the external voltage is impractical. However, they can be dimmed using pulse-width modulation (PWM) dimmers. These rapidly switch the LEDs on and off, typically 20 times per second, by changing the voltage from zero to the expected value as a square wave. The relative width of the on and off portions of the square wave can be varied so that the LEDs are on or off for relatively more or less time, leading to a perceived (and to some extent real, with phosphor-coated LEDs) change in the brightness.
Strip lights are designed for both indoor and outdoor use depending on whether they’re water resistant. Since the strip is flexible and can be divided at any point between LEDs, it is extremely versatile and can be used in a number of installations. Outside of traditional lighting, strip lighting is extensively used in DIY projects or lighted clothing. The ability to power strip lights off of a USB device or battery pack makes them extremely portable. Examples include: Computer lighting, costume lights, toys, workspace lighting, monitor and display ambient lighting, and alcove lighting.