Constant voltage drivers are becoming more popular lately. They’re safer, flexible, and often cheaper than their constant current counterparts, but it can be a little more difficult to pick the right CV driver for your system than it would be for a CC build. Don’t sweat though, it’s really not very hard. All you need is an understanding of how parallel wiring works and to know how to manipulate forward voltage and current numbers using data sheets or product simulators.
Below are the steps to take to find a suitable constant voltage driver. Continue reading
- Select a COB from the dropdown
- Enter the quantity of COBs
- Select a drive current.
The spreadsheet will calculate your total forward voltage and highlight all of the Mean Well HLG-C drivers that are compatible with the parameters you entered. All data is pulled from manufacturer product simulator tools. If the total forward voltage (Vf Total) of your system falls within the rated constant current range of a driver (between V_min and V_max), that driver will turn green, indicating it is a match. I welcome any and all feedback on how to improve this tool – if you notice an error, have a suggestion, or would like to see other COBs or drivers, leave a comment.
Please note that even though big drivers may be capable of driving tons of COBs in series at low current, the high voltage generated by wiring the COBs in series may exceed the rating of your COB holders or connectors (a number of common holders are rated for a maximum of 250V – this would equate to a max of about 7x 36V COBs in series per driver). Always check your equipment specs to verify it can handle the total voltage.
UPDATE 04/17/2017: Citizen CLU COBs updated to Version 6 (F1), Quantum Board 288 and 304 models added.
UPDATE 05/30/2017: HLG-480H-C Drivers added.
UPDATE 06/16/2017: 72V Cree CXB3590 added.
When you’re designing a COB LED system, it can be difficult to compare COBs of different brands or models with one another. If you were to try to do it just by looking at the data sheets for each model, you likely wouldn’t quite end up with the exact numbers you were hoping to get, and would have to base your estimates on graphs, then do a bunch of math. Nobody likes math.
The easiest way to compare COB specs is by using the manufacturer’s simulation tool. Most manufacturers release a spreadsheet that allows you to input certain values and then spits out a number of different specifications. If you have an idea of the color temperature, voltage, or current you’d like to run at, you can plug these values into the spreadsheet and see how the various specs interact with one another.
Want to figure out how much light your COBs are giving your plants? Getting an accurate measurement is a little trickier than you might think.
A quick glance at your standard COB data sheet will probably show you one related specification: its luminous flux rating. While luminous flux is a good indicator of how bright a COB is at a certain wattage compared to others, it’s not the ideal way to quantify how much light your plants are getting. There are many different units and methods used for measuring light, like luminous flux, lux, foot-candles, PPF, and PPFD. Let’s have a lil’ gander at each.
After sifting through my posts, I realized that I’ve neglected to write something that’s a little more suitable for somebody who’s brand spankin’ new to the world of LED COBs. This guide will serve as a short introduction to the basic elements of COB LED lighting systems, and is a good place to start if you’re looking to make the switch from other types of lighting, or if you’re new to indoor gardening altogether.
COB LED systems are actually quite simple – there are only a handful of different parts, and they all go together pretty easily. The main components of a COB LED system are:
- The COB LEDs themselves
- Heat sinks that the COBs are mounted to
- LED drivers that power the COBs
- The wires that interconnect the COBs and drivers.
Not so bad, right? Let’s delve a little further in.
Due to the low-current nature of most LED light systems, most of the wire you find lying around should do the job. There are, however, a few considerations you should make to ensure what you’ve got will fit the bill.
When it comes to wiring LED COB circuits, series configurations with constant current drivers are generally the easiest way to go – especially if you’re new to electronics. Since LEDs are semi-conductors and operate a little differently than most basic circuits, it’s far easier to simply drive them at their rated current with a constant current driver than it is to try and produce that current by providing a constant voltage. If you check the datasheet and find that your LED COB has a typical forward voltage of 36V at 2400mA, you don’t want to strive to give the LED 36 volts, you want to strive to give it 2400mA at whatever voltage that current happens to occur at.
There are 2 ways to go about wiring LEDs: series and parallel. In most cases, if you have a constant current driver, you’re going to want to wire them in series. If you’re using a constant voltage driver, chances are, you’ll be wiring in parallel. You may even need to combine both methods in order to hit a certain voltage or current to match to a particular driver (see my post on matching COBs to drivers for more info on this). This information applies to LEDs of all types, whether they’re COBs, boards, strips, or whatever.
Time for another quick guide. In this one, I’ll go over how to use a digital multimeter to check 2 important characteristics of your LED COB circuit: voltage and current. If you haven’t worked much with electricity, I’d recommend brushing up on the very basics, so you can minimize your risk of zapping yourself. These circuits can be very powerful and you need to exercise caution when working with the voltages and currents inherent to high-powered LED systems. Be careful!