But, in general, it’s important to make sure that your input voltage into the driver can deliver an output voltage equal to or greater than the 8.85V we figured out above. For a deeper understanding of LED drivers take a look here. As LEDs heat up their forward voltages change, so it’s important to use a driver that can vary its output voltage but keep the same output current. In the beginning, we mentioned using a constant current LED driver because these power modules can vary their output voltages to match the series circuit. So theoretically, 8.85V is the minimum required input voltage to drive this circuit. The sum of three of these LED forward voltages is equal to 8.85V DC. Let’s take a look at this by using the above circuit again as an example and let’s assume the LED is a Cree XP-L driven at 1050mA with a forward voltage of 2.95V. This means you have to supply, at minimum, the sum of the forward voltages of each LED. The second bullet point above states, “The total voltage of the circuit is the sum of the voltages across each LED”. The loop concept is no problem by now and you definitely could figure how how to wire it, but how about actually POWERING a series circuit. Varying voltages across each LED is okay.Series circuits are easier to wire and troubleshoot.If one LED fails, the entire circuit won’t work.The total voltage of the circuit is the sum of the voltages across each LED.The same current flows through each LED.Here are a few bullet points for reference about a series circuit: Finally, the last LED connection goes from the negative of the LED to the negative output of the constant current driver, creating a continuous loop or daisy chain. The image to the right shows an example: To wire a series circuit as the one shown, the positive output from the driver connects to the positive of the first LED, and from that LED a connection is made from the negative to the positive of the second LED and so on, until the last LED in the circuit. Often referred to as ‘daisy-chained’ or ‘looped’ the current in a series circuit follows one path from start to finish with the Anode (positive) of the second LED connected to the Cathode (negative) of the first. When each LED is receiving the same current it helps eliminate issues like thermal runaway.ĭon’t worry, a parallel circuit is still a viable option and used often later we will outline this type of circuit.įirst, though, let’s wrap our heads around a series circuit: This means each LED in the circuit will be the same brightness and will not allow a single LED to hog more current than another. Running a series circuit helps to provide the same amount of current to each LED. The requirements of a lighting application often dictate what type of circuit can be used, but if given the choice, the most efficient way to run high power LEDs is using a series circuit with a constant current LED driver. Is one better than the other…Series, Parallel, or Series/Parallel? Let’s get started with the most basic question… With years of providing LED education, training, and explaining the electronic circuit concept to customers, we have gathered and prepared all the critical information needed to help you understand the concept of electrical circuits and their relationship to LEDs.įirst things first, don’t let electrical circuits and wiring LED components sound daunting or confusing – connecting LEDs correctly can be simple and made easy to understand if you follow this post. It’s likely though, that you’ve already read the Wikipedia page about Series and parallel circuits here, maybe a few other Google search results on the subject, and are still unclear or want more specific information as it pertains to LEDs. Hopefully, those looking for practical information on electrical circuits and wiring LED components found this guide first.
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