We created a board for driving RGBW COB (Chip-On-Board) LEDs. We also sourced some RGBW (red, green, blue, white) COB LEDs, and heatsinks to put together a complete LED lamp kit. The drivers are constant-current source drivers based up the same topology as a buck switching regulator, so there is very little heat generated by the drivers. The other advantages of the driver, and the reason that switching regulators have taken over the world, is that any voltage supply may be used (at or above 12V) without losing efficiency. In other words if the supply voltage is raised, the current draw at the supply is reduced while the current supplied to the LEDs will remain constant.
The COB LEDs however do get hot, and definitely need a heat sink. We put a thermistor on the board, with a voltage divider, so you can monitor the heat on the heatsink if you are using a microcontroller board.
We also sourced the COB leds and the heatsinks so we can provide this either as a complete kit or an complete assembly.
A great thing about the LED driver we found is that the LED AL8861 driver chip inputs can accept an analog input, as well as PWM, allowing you to build a nice variable color RGBW lamp with only four potentiometers. The driver board inputs work equally well with PWM outputs from an Arduino or other microcontroller, and dim easily from 0 to 100% in a nice linear curve. The driver board will accommodate either one or two COB LEDs with currents up to 600 mA.
There is also nothing to say that you couldn’t drive a whole host of other types of LEDs such as 24 or our 1 watt LEDs arranged in a 3 series x 2 parallel x 4 channels, or 120 5mm LEDs arranged in 3 series x 10 parallel x 4 channels. The mind boggles at the possibilities.
Some custom applications might include:
- Controllable LED signage
- Custom / DIY LED Lamps
- Theatrical Lighting
- Grow Lights
- Colored Strobe Light Experiments
- Impressive and blinding Halloween costumes
Specifications for the COB LEDs:
These are the specifications from the manufacturer for one COB LED.
We’ll have product links up as soon as get done editing the product pages. Also a discount code for the first few buyers.