Resistors will be needed in all cases when driving LEDs from a voltage source, unless you are using LEDs that already have a built in current limiting IC inside the package (a few do these days, for example I have some blinking LEDs that need no resistor they have a blinker IC built in that also limits current).However you have another problem that you obviously are not aware of. 8 LEDs rated at 1.5V in series totals exactly 12V. But your battery is only rated at 12V. As the battery discharges its voltage slowly drops, the moment it drops under 12V all the LEDs will turn off! I strongly recommend that you use no more than 7 LEDs rated at 1.5V in a circuit powered by a 12V battery, so that the battery can actually gets a chance to discharge beyond its knee voltage. In this case the resistor will drop the remaining voltage, whatever it is depending on the charge state of your battery.
LEDs will typically reduce their light output throughout their life after an initial increase above the rated light output.This degradation will usually be a near-linear reduction.Well-made LEDs will not normally fail catastrophically, but drop in their output until they are no longer useful.High quality LEDs are typically rated to drop to 70% of initial light output after 50,000 hours for white LEDs, and 100,000 hours for all other colours.
A: It sure can but what is voltage iof the LEDS 3.2 V then you need to drop 3.7 to 3.2 v at ~20ma .5v / 0,02=27 ohms in series the LEDS are 1.8 you need 3.7- 1.8/.02= 100 ohms in series. The warning is the life of this setup is going to be short lived after the battery drain off the battery needs recharging if so it is better to supply the LEDS from the charger directly will last until the LEDS QUIT FUNCTIONING
With their emission properties Superluminescent Light-Emitting Diodes (SLEDs) are closing the gap between Laser Diodes (LDs) and Light Emitting Diodes (LEDs).They offer the broadband optical spectra of LEDs and the spatial coherence of LDs. Compared to Laser Diodes and LEDs, SLEDs can be understood as • Spatial coherent broadband laser diodes with a beam-like output • Temporal incoherent laser diodes with a broadband spectrum • Speckle-free laser diodes with a short coherence length • Spatial coherent LEDs with a beam-like output
20 led can be powered from a single 4017 output X-ZONE ( PRANJAL)
No, not all LEDs are dimmable. Some LEDs are designed to be dimmable, while others are not. It is important to check the product specifications to see if an LED is dimmable before attempting to dim it.
If your compairing apples to apples like 3 watt leds to 3w leds then 128. The more leds the higher the power.
Yes, LEDs are dimmable.
Basically, when LEDs are connected in parallel, the LEDs with the lowest resistance will be the brightest, the other LEDs will be dimly lit or not lit at all. Therefore, use LEDs with the same model number and colour.
No.
red, green, yellow, blue leds
There are several types of LEDs, including standard (through-hole and surface mount) LEDs, which are commonly used for indicators and displays; high-power LEDs, designed for applications like lighting; and RGB LEDs, which can emit multiple colors by combining red, green, and blue light. Additionally, there are specialized LEDs such as organic LEDs (OLEDs) for displays, and ultraviolet (UV) LEDs for applications like sterilization and curing. Each type has unique properties suited to specific applications in electronics, lighting, and displays.
Most modern torches have LEDs in them, several newer models of Audis do too.
It depend on what the rating voltage of the LEDs are.
SemiLEDS Corporation (LEDS) had its IPO in 2010.
Resistors don't light up LEDs. They're required in a circuit along with LEDs in order to prevent excessive current through the LEDs when the LEDs are forward biased. The correct resistance value depends on the supply voltage and the desired (rated) current through the LEDs, and there's typically one resistor in series with each LED.
The difference is that LEDs use less electricity.