How to choose the right LED driver?

Step 1: Identify if your LED fixture is current- or voltage-driven

LEDs run on constant current, but fixtures can be controlled in two ways. Always check the packaging to see if the fixture is current- or voltage-driven.

Constant current drivers are designed for current-driven fixtures, maintaining a steady current (e.g., 500 mA) while the voltage varies (e.g., 2 ~ 90 V). These drivers convert mains power directly into constant current and should never be used with voltage-driven fixtures.

Example:

• One recessed downlight + driver


• LED downlight specs: current-driven, 700 mA, 17 W, 24 V minimum voltage


• Driver: constant current driver of 700 mA with an output voltage range that includes 24 V (e.g., 2 ~ 86 V).

Constant voltage drivers are used for voltage-driven fixtures, maintaining steady voltage (e.g., 12 V) while the current varies (e.g., 0 ~ 0.8 A). These drivers are suitable for most fixtures as long as they have a current limiter or electronic circuit.

 

Step 2: Determine the power requirements

When connecting multiple fixtures to one driver, ensure the driver’s capacity matches the total power and the number of fixtures.

Current-driven LEDs are wired in series, where the current flows through a single path and all fixtures receive the same current. Voltage is evenly distributed.

Example:

• Three spots, powered by one driver


• Each LED spot: current-driven, 700 mA, 3.2 W, 4.5 V minimum


• Driver: constant current driver of 700 mA with an output range covering 13.5 V (e.g., 9 ~ 30 V), calculated by multiplying the voltage per spot (4.5 V) by the number of spots (3 x 4.5 V = 13.5 V).

If the number of fixtures is uncertain, consider a constant voltage solution. Voltage-driven LEDs are wired in parallel, where multiple circuits can share the load.

Example:

• Three spots, powered by one driver


• Each LED spot: voltage-driven, 1 A, 12 W, 12 V


• Driver: constant voltage driver of 12 V, with current capacity of 3 A (three spots each draw 1 A).

 

Step 3: Does your lighting need to be dimmable?

Before installation, ask whether dimming is required. Dimming impacts both the LED and driver choice. There are two primary dimming methods for LED lights:

• Regulating the current to adjust brightness


• Rapid on-off switching to reduce perceived brightness.

Choose dimmable LED lights and drivers
Ensure both the LEDs and drivers are dimmable by checking the product specifications. Both constant voltage and constant current drivers have dimmable options, but most standard drivers are not dimmable and are designed for on/off use only. Additionally, consider the environment — outdoor drivers should have at least IP65 protection.

Select a dimming protocol
The dimmer (whether a switch or smart device) must be compatible with both the lighting and driver. The appropriate protocol depends on your specific application.

Example:

• Eight dim-to-warm spots, powered by one driver


• Each spot: current-driven, 180 mA, 6 W, 33 V


• Driver: constant current driver of 180 mA with an output range covering 264 V (e.g., 90 ~ 290 V), dimmable via 0-10V or PWM.

For more advanced setups, such as color-changing features, consider systems like DALI-2, Zigbee 3.0, DMX, Niko, or Casambi, which allow wireless control via smartphones or tablets.

Example:

• Three multi-color spots, powered by three drivers


• Each spot: current-driven, four RGBW channels, 1 A per channel, 52 W total, 13 V minimum


• Driver: constant current driver of 4 x 1 A (four channels), with dimming options via Casambi (Bluetooth) or DALI-2.

Choose quality drivers
Quality is crucial when selecting an LED driver. While safety standards ensure basic protection, many manufacturers use the cheapest components, compromising durability and reliability. Always prioritize quality to ensure long-lasting, dependable performance.