No one needs to be convinced about the benefits of using LEDs in lighting. A pre-presented power supply provides the correct diode performance. This system is a surge current stabilizer. The circuit diagram is shown in Fig. 1.
In fig. 2 shows the characteristics of the output current as a function of the resistance PR1.The change range is from 50 mA to 1.2 A. The MBI1801 chip has built-in thermal protection that protects it from damage. When the temperature reaches 165 ° C, the output is switched off. The device consists of only eight elements and is not difficult to assemble. After assembly, only adjustment of the output current is required. The easiest way to do this is to connect the ammeter in series with the LEDs. Before turning on the power, potentiometer PR1 must be set to maximum resistance. The input supply voltage should be approximately 2 ... 3 V higher than necessary for the diode. Now turn on the power and set the required output current using the PR 1 potentiometer. It may also turn out that with a limit of the output current and voltage of the power source, the MBI1801 chip will need a radiator. It should also be remembered that the minimum supply voltage must be at least 6 V.
