This is a linear LED constant current driver that can provide up to 700mA of current to drive LEDs.
While switchmode drivers are usually very efficient, they can have the drawbacks of higher complexity, lower reliability, higher cost and electrical noise generation.
This linear driver produces no electrical noise at all. By selecting a power supply voltage close to your LED voltage, you can achieve efficiencies similar to switchmode drivers.
For example, if you drive three white LEDs in series (with a total Vf of 10.5V) from a 12 volt supply, the efficiency using a linear supply can be 85%.
This driver requires just 350mV of voltage overhead at a LED current of 500mA and is thermally protected.
The driver also has an enable/PWM pin for LED dimming, and the LED current can be set to anywhere between 100 and 700mA simply by adjusting the onboard trimpot.
Instructions for this kit are here. The datasheet for the main IC used in this kit, the ADDtek AMC7140, is here.
Note: the pin spacing of this IC is 1.27mm, so you will need a fine tipped soldering iron and reasonable soldering skills to make this kit.