20 Watt LED Current Measurement

Please let me know that what is the current consumption of 20 Watt LED .

Please find attachment.

You have to check with the shop what voltage the LED is for, the current will be 20W/voltage.
My guess is that the voltage is about 20V and the current is 1A.
If you can't find the voltage then you have to measure it. Connect to the LED variable power supply in series with 100 ohm. turn up the voltage until you get light, the voltage of the supply is the voltage of the LED.

Dear Vbase,

Sorry I did not mention its voltage its 12V 20W.

But 20W is not actual power, its light intensity is equal to 20W Light. but actual power is low.

Light is measured in lumens and your LED supposed to be about 2000 lumens. It is like filament bulb of 100W
When the LED is specified as 20W this is the actual power that the LED will dissipate, 1.66A at 12V.

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imranahmed said:

Dear Vbase,

Sorry I did not mention its voltage its 12V 20W.

But 20W is not actual power, its light intensity is equal to 20W Light. but actual power is low.

Click to expand...

The LED that you have has to be mounted on a heatsink of about 100x100 mm.

The 12V 20W LED has 20 dots. I think each dot is a 1W LED on the chip. Each white LED uses about 3V so this one has 5 groups in parallel of 4 LEDs in series.

Current consumption of " Any " 20 W device at 12 V must be 1.667 A

as I = W / V

imranahmed said:

But 20W is not actual power, its light intensity is equal to 20W Light. but actual power is low.

Click to expand...

There is no such thing as 20W of light. Light intensity is measured in the amount of Lumens. An old 100W incandescent light bulb produces less intensity as a 20W LED. 20W is the amount of heat it produces when it has its rated current.

The PICTURE that you posted is Definitely a 20 Watt LED.
Not by the Amount of Light it gives off, But by the Actual POWER it Requires.
So 12 Volts at 1.6 Amps to run it.
And as stated above, it Needs a GOOD Heat-Sink Solder to it to keep it from being Damaged by excessive heat.

It will give you a VERY BRIGHT LIGHT!

Isn't 20W its maximum allowed power? Are any of them actually running (burning?) at 20W? Maybe if it is turned on and off a number of times at 20W then it would shatter due to thermal expanding and contracting.

No it Doesn't Shatter.
It will run Continuous or Intermittent use at that Current Level, With a Proper Heat-sink.
I have Many of these that I use in Both Situations.

They are Really Bright.
Not Good to look Directly at them.

The input power to the LED is 20W. The light output is approx 1500-2000 lumens. This value depends on the phospors used in the LED (cool/warm white etc) and the effective light energy will be less than 5W of visual radiation. The rest of the energy is dissipated as heat. The conversion of lumens to watts is dependent on the spectrum of the visual light emitted.

Each led gets 3V (each group has 4 led dots in series) and about 300mA (1.66A/5- there are 5 branches). It produces a monochromatic light (bluish green or greenish blue) that is converted into white light using a phosphors (similar to the ones you see inside the CFL lamps). This conversion too is not highly efficient. These LEDs can be flashed at very high frequencies (not MHz; because of the phosphors) and nothing is going to happen if you use a good heat sink and do not exceed the voltage. If you can plot the I-V curve of the LED assembly you will see the reason why it is a bad idea to exceed the recommended voltage. Also the light output decreases with temperature.