A regular regulated power supply keeps the output voltage constant when the load changes. The constant current module is a type of power supply that maintains a constant output current when the input voltage changes. Before use, it is necessary to understand its various characteristics.

1. Current setting: Generally, the output current of a constant current module can be adjusted within a large range according to user requirements, as long as the output current setting resistance is simply changed.

2. Type: There are three types of constant current modules: boost type, buck type, and boost/drop type. The choice of which one is entirely determined by the relationship between the required input voltage and output voltage. But from the perspective of achieving maximum efficiency, then the depressurization type should be chosen. The buck type refers to the input voltage being relatively high. So the input current is relatively small, so the loss caused by copper loss is relatively small, and buck constant current modules usually have higher efficiency. Therefore, it is also necessary to minimize the number of LEDs connected in series in the load, in order to use a step-down constant current drive module.

3. Relationship between input voltage and output voltage

Whether it is a step-up or step-down constant current module, the closer the step-up or step-down ratio is to 1, the higher the efficiency. Of course, it cannot be equal to 1, and 2-3V must be reserved for constant current module consumption. And this is entirely determined by the overall design of the street lamp. So when designing the overall street light, it is necessary to consider this factor to select the number of LEDs connected in series with the power supply voltage and load. Instead of requiring a constant current module to provide high efficiency once it is designed.

4. Dimming ability: Constant current modules usually have dimming ability, and this dimming ability is not simply adjusting their output current, but using a dimming method called pulse width modulation (PWM), which utilizes the fast switching ability of LEDs and the visual residue of the human eye, causing changes in the brightness of the appearance. Thus, the chromatographic changes caused by adjusting the current are avoided. This dimming ability is very important in street light design, as utilizing this performance can change the brightness of the street light according to traffic flow, further achieving the goal of energy conservation.

Below, we will discuss two situations: solar LED street lights and commercial LED street lights.