Gdetrailer wrote:
Wrong.
You need to understand just HOW these LEDs are wired..
I have one of these same LED modules that Mex has so I am very aware of the design and not to mention I have MEASURED current draw of said modules..
These modules are known as COB or chip on board. They are an array of 1W LEDs mounted on a plate.
There is three parallel ROWs of LEDs, each row has THREE WHITE LEDS in series..
Each white LED requires 3.4V to light so each ROW requires about 10.2 V..
Each ROW only consumes about 1W since LEDs in series share the same amount of wattage like a resistor in series)
Each row is 1/3 of the current draw (and wattage) but all the LUMENS are added together..
So technically all three parallel ROWs added together will draw about 3W at 10V if you really wish to be accurate..
The manufacturers kind of skew the actual wattage drawn since they add up the wattage of all the chips on the board.. Technically it is a 9W module but they round it up to 10W for marketing purposes.. But in reality it is drawing not much more than 3W at 10V..
Wattage (for a DC circuit) is defined as voltage times current. Each of the LEDs in a chain does of course see the same current, but since the voltage across the three LEDs is three times the voltage across a single LED, the power is also three times as great.
If you power nine 1W LEDs to full brightness, they are consuming 9W of power, regardless of whether they're wired in parallel (about 2.6A at 3.4V) or in series (0.26A at about 34V) or in some other manner (maybe 0.88A at 10.2V).
Resistors in series also behave the same way at a given voltage and current. (Resistors do, of course, exhibit different behavior than LEDs in relation to changing voltages.) A resistor that dissipates 1W of power, if put in series with other resistors with the voltage increased such that the current remains the same, will still dissipate its 1W of power while its companions also dissipate additional power. Likewise, If you connect two 1500W 120VAC heaters in series (they're essentially resistors, after all), and then connect the whole to a 240VAC circuit, the heaters consume a total of 3000W and put out 3000W of heat.
