Living in the beautiful state of Vermont and working for a company like LEDSupply that is helping provide LED products to save on energy is a great place to be in accomplishing this. LEDs that are rated to operate on a constant current driver require a designated supply of current usually specified in milliamps (mA) or amps (A). LED drivers are the driving force that provides and regulates the necessary power to make sure the LEDs operate in a safe and consistent manner. Most often, constant voltage drivers are implemented in under-cabinet lights and other If you take a look at high powered LEDs, one unique characteristic is the exponential relationship between the applied forward voltage to the LED and the current flowing through it. In the example above we would still be alright driving the XP-G2 LED at 700mA, however, if you didn’t have a current limiting device, the LED would draw more current as it’s electrical characteristics changed due to temperature increase. So if you see that your strip takes 12VDC, don’t worry about a constant current driver, all you will need is a 12VDC constant voltage source as the current is already being regulated by on board circuitry that the manufacturer has built in.So when you’re building your own fixture or working with our You use a constant voltage LED driver only when using an LED or array that has been specified to take a certain voltage. Most common constant voltage drivers (or Power Supplies) are 12VDC or 24VDC. Higher current ratings do make the LED brighter, but if not regulated, the LED will draw more current than it is rated for. This would eventually push the current way above the limit…especially in hotter environments. We call this thermal runaway which is explained in more detail The above example is with high powered LEDs and on a smaller scale as we only talked of using one LED. LED drivers are the driving force that provides and regulates the necessary power to make sure the LEDs operate in a safe and consistent manner. Understanding the difference between the two types can:Constant current LED drivers are designed for a designated range of output voltages and a fixed output current (mA). The manufacturers make sure the resistors are of the right value and in the right position so that the LEDs on the strips will be less prone to the variation of the voltage source as we talked of with the XP-G2.
This is the type of power that is typically output from your wall outlets around the home. See Figure 2 for Cree’s specifications of the maximum forward current and the de-rating curves in different ambient temperature conditions. These drivers vary the voltage along an electronic circuit which allows current to remain constant throughout the LED system. When the LED is turned on, even the smallest 5% change in voltage (2.74V to 2.87V) can create a 100% increase in current driven to the XP-G2 as you can see at the red marks current went from 350mA to 700mA.Now higher current does make the LED brighter, but it also will eventually over-drive the LED.
A constant current driver is the best way to drive high power LEDs as it maintains a consistent brightness across all LEDs in-series.Constant voltage drivers are designed for a single direct current (DC) output voltage. An LED light that is rated for constant voltage usually specifies the amount of input voltage it needs to operate correctly.A constant voltage power supply receives standard line voltage (120-277VAC). The driver will always maintain a constant voltage no matter what kind of current load is put on it. The excess forward current would result in extra heat within the system, cut down on the LEDs lifespan, and eventually ruin the LED. Constant Voltage Drivers switch this alternating current voltage (VAC) to a low direct current voltage (VDC). An example of a constant voltage power supply is below in the The LPV-60-12 will maintain a constant 12VDC if the current stays below the 5-amp maximum shown in the table. Since their current is already being regulated, all they need is a constant voltage to power the LED(s).When LEDs or an array of LEDs are constructed like this they will typically state a voltage to be run at. With lighting in the real world, it isn’t convenient or economical to build everything by hand from a single diode, LEDs are usually used together in series and/or parallel circuits to create the desired outcome. Understanding the difference between the two types can: Fortunately for lighting designers, manufacturers have introduced many LED products to the market that have multiple LEDs already assembled together like LED rope light, LED strips, LED bars, etc.The most common LED strips are designed with a group of LEDs in series with a current-limiting resistor in line with them. Thermal Runaway refers to excess current beyond the LEDs maximum drive current which results in drastically lower LED life-spans and premature burn outs due to increased temperature. Always exploring and staying active outdoors while keeping a close eye on different trends and new technologies that could change the world for the better.Guide to Soldering LEDs: Save time & money with these helpful tips!How to Dim Your LEDs: Top 3 Solutions for Smooth LED Control This is helpful as:Marketing and technology enthusiast helping pave the way to a more energy efficient society.