So I didn't see anything on these great inexpensive LED light bars, so I thought I would start a thread on them. They can be found many different places on line, form different vendor/manufactures but they all seem to be based on the same design and aluminum extrusion. The Nilight brand is an example of one of the better versions I have gotten, It feels like they may have used better binned LEDs and heavier gauge cable. You can get them in either a spot with smooth reflectors or flood with stippled reflectors for a wide beam. In my opinion the spot is best for driving type applications. The flood is probably better for lighting up an area like the bed of a truck or camp sight. I have put 4 different sets of these on off road vehicles in the past few months.
All the ones I have seen in this styling have used Cree XB-D LEDs and a PT4115 1.2A buck driver which allows a voltage input from about 11-30Vdc. The 18W lights use 2 drivers each driving 3 series LEDs. All this is laid out on one large MCPCB, Here are 2 different examples, same circuit in a slightly different layout.
The claimed 18W is a just more bogus specks. The ones I have gotten have actually had in input power draw of about 12.5W with about 11 of those watts being delivered to the LEDs (the biggest portion of the loss being the reverse polarity protection diodes). They have used a 0.16 ohm sense resistor which yields 625mA per LED. The LEDs are rated for up to 1A and the driver chip is rated for up to 1.2A. I have replaced the sense resistor on some of mine with a 0.10 ohm resistor which drives the LEDs at 1A and total power consumption goes up to about 20W. With the power upgrade the heat sink can get fairly hot. But I am usually using these modified ones in a moving environment where they get lots of air flow. At stock power levels the heat sink is more than sufficient for running them in a stationary environment with little air flow. To be honest the brightness increase form 12.5-20W is not proportional to the power increase, yielding only a slightly brighter light. This is probably whi the factory chose the drive level they did even though the components are capable of much more. The brightness increase s minimal but heat and power consumption is much more.
One fun think I did with one of these lights is add a potentiometer to be able to dim the lights and then use it to make a Ryobi tool battery powered flood light.
I tied the dim pin (pin3) on each driver together and then connected that through a 100K potentiometer and a 9.1K resistor to ground. The result is I can go from off to 2W and then gradually up to 20W power draw.
I hacked up an old Ryobi type dust buster vacuum to make my lighting project.
All the ones I have seen in this styling have used Cree XB-D LEDs and a PT4115 1.2A buck driver which allows a voltage input from about 11-30Vdc. The 18W lights use 2 drivers each driving 3 series LEDs. All this is laid out on one large MCPCB, Here are 2 different examples, same circuit in a slightly different layout.
The claimed 18W is a just more bogus specks. The ones I have gotten have actually had in input power draw of about 12.5W with about 11 of those watts being delivered to the LEDs (the biggest portion of the loss being the reverse polarity protection diodes). They have used a 0.16 ohm sense resistor which yields 625mA per LED. The LEDs are rated for up to 1A and the driver chip is rated for up to 1.2A. I have replaced the sense resistor on some of mine with a 0.10 ohm resistor which drives the LEDs at 1A and total power consumption goes up to about 20W. With the power upgrade the heat sink can get fairly hot. But I am usually using these modified ones in a moving environment where they get lots of air flow. At stock power levels the heat sink is more than sufficient for running them in a stationary environment with little air flow. To be honest the brightness increase form 12.5-20W is not proportional to the power increase, yielding only a slightly brighter light. This is probably whi the factory chose the drive level they did even though the components are capable of much more. The brightness increase s minimal but heat and power consumption is much more.
One fun think I did with one of these lights is add a potentiometer to be able to dim the lights and then use it to make a Ryobi tool battery powered flood light.
I tied the dim pin (pin3) on each driver together and then connected that through a 100K potentiometer and a 9.1K resistor to ground. The result is I can go from off to 2W and then gradually up to 20W power draw.
I hacked up an old Ryobi type dust buster vacuum to make my lighting project.