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I am comparing driver specification with the LED specification.
Driver output voltage is 700 mA at 4.5 V.
Here current rating is less than the LED, but voltage rating is higher than forward voltage.
I am wondering whether higher voltage might damage the LED.
Appreciate if someone can suggest and verify the product choice.
Leds are more current based than voltage . The current being less on that part would make the led less bright as it could not draw enough current . It should still light up. It just would not get as bright. I did find part number 4797-SMT-M-040CT-ND. This one is a little higher on the current. It would handle the voltage also.
@Verna_1353 picked out our best option 4797-SMT-M-040CT-ND (SMT-M-040CT), however just make sure to have the DIP code properly set to 1.3A before powering on to reduce risk of burning out the LED. I would assume the driver would be factory set at its lowest 300mA current rating. Being your LED is rated 1.3A MAX, you could possibly go lower in amperage to prolong LED lifespan, whereas running at 1.4A would likely burn it out much sooner. Other things to keep in mind regarding LED lifespan is the ambient temperature, if it is in a bezel or luminaire, and whether or not an extra heatsink or fan would be required.
IF your LED has a built in resistor, using a constant voltage driver like 1866-4131-ND (RS-15-3.3) would be another option, however the power cord is sold separately.
Thanks Ryan.
I went through datasheet yesterday. Adjusting the DIP switch can fit the output in LED specs. I have mounted LED on fin base for better heat dissipation.
Thanks for product suggestion.
Yes, LED are current based devices but there should be some kind of limit on maximum voltage one can apply… just curious.
Constant current controlled LED drivers adjust voltage as necessary to source the current they specify. The only limits on this are the voltage minimum and maximum limits specified for the driver. As long as the LED or LED string’s specified forward voltage value falls within the minimum and maximum limits of the constant current driver, it will work.
Correct, you do not want to exceed the maximum voltage (or current) ratings of an LED. Exceeding either of these values will damage the LED.
However, that is strictly looking at the voltage and current at the LED itself. A power supply driver will often have more current OR voltage which adjusts to the LED. This is why choosing a driver with the correct specifications is critical to prevent LED failure.
Example
If using a Constant Voltage (CV) driver for LEDs with integrated resistor, the output voltage must match LED voltage requirements, but the output current of the driver must be rated equal or preferably higher than the LED current.
If using a Constant Current (CC) driver, the voltage of the LED must fall within the driver output voltage window, and the current must match (or slightly below) the maximum LED current requirements, although it is best to use the nominal or test rated LED current instead of the absolute maximum rating.
As per driver RACD03-700 you selected, in its CC Mode which it would automatically revert to, although the voltage is correct since the 3.3V of the LED falls within the voltage output window of the driver, the amperage may be too low at 700mA which may produce a dim LED (depending on the actual rated LED test current).
