Controllers achieve striking LED flexi strip displays

Minimal cutting lengths and bending diameters, together with extended continuous lengths and new design connectors facilitate seamless lighting exactly to customer requirements. Ultra-high brightness LEDs ensure high levels of illumination.

However it’s the associated electronics - the drivers, controllers and other accessories - that ultimately allow users to realise the full potential of their LED flexi strip installation. Large areas of coverage, multiple zones, each with a choice of scenes and preset colour-changing modes can all be managed from wireless remote controllers. RGB adjustments and dimming can be handled from the same units. Integrations with DALI controllers and simpler schemes with dimming only can also be set up.

Below we look at some of the LED drivers and controllers now available, and how they can be used together with flexi strip LEDs to achieve application-specific, tightly-controlled lighting environments and moods.

From a user’s perspective, two obvious features of a lighting installation - LED or otherwise - are its brightness and its colour; these may be static, or varying over time in a more dynamic and arresting display.

Colour, and its ability to vary, depends on both the Flexi Strip and its control electronics. The Flexi Strips can be classified into three types according to their colour characteristics. Firstly, there are fixed-colour products; PowerLED's Nautilus NTS-IP67-5700K-W, for example has LEDs with a white colour output fixed at 5700K. For colour displays, the NTS-IP67-RGB-W can be used. This accepts an RGB input and its colour output can be controlled by varying the ratio of the R, G and B signal inputs.

A white output can be set up using the appropriate RGB ratio. However this is not suitable for all applications as it has a bluish tinge. Instead, a product such as PowerLED’s F10-RGBW-12-60-IP68 can be used, as this has both RGB colour and white LEDs mounted in parallel along the strip’s PCB. This enables true white and RGB colours to be achieved in one location without the need to install two strip types. The strip has four input signals - R, G, B and W.

Devices such as PowerLED’s RGBRF-4x5A which provide R, G, B and W signals are suitable for both RGB and RGBW Flexi Strip types. The RGBRF-4x5A is referred to as a receiver because it is controlled remotely, via a wireless link, from handheld unit RGBRF-RC1. This has a user-friendly interface that allows operators to manage up to six zones of 12 – 36VDC LED strips and set six scenes in each. (A scene is a colour setting). Millions of colours are available through different brightness settings for each channel - R, G and B. Up to 10 colour changing modes can be preset, and a Pause function is available. One RGBRF-RC1 controller can run six independently driven RGBRF-4x5A receivers, and, if required, changing mode sequences can be synchronised across all of these. Figure 1, below, shows the handheld controller and receiver.

Figure 1 - PowerLED RGBRF-RC1 controller and RGBRF-4x5A receiver

Other alternatives exist: The RGB18 can control 12 or 24VDC RGB or RGBW strips, and can set up colour scenes with adjustable speed change and brightness. Five levels of brightness are possible with RGB colours and 10 for White. Ideal for creating visual effects, the RGB18 allows an inconspicuous installation within retail, domestic and internal applications and has IP63 ingress protection.

If required, outputs from both RGB18 and RGBRF-4x5A can be amplified with the 4-channel PRDIM LED power repeater, offering up to 180W per channel. Additional Flexi Strips can be driven from one controller.

For simpler schemes involving fixed single-colour LED strip installations, controllers such as PowerLED’s PD2021 are available. This operates from a single pushbutton to provide on/off control and a 256-level dimming function.

All of these controllers, however, depend on reliable AC/DC power supplies for successful operation. Mean Well’s HLG-185H-24B, for example, provides over 187W of power at 24V - enough to support several metres of Flexi Strip. The unit has short circuit, overload, over-voltage and over-temperature protection as well as compliance with worldwide safety and EMC regulations for lighting. Many different Mean Well power supplies with equally comprehensive qualifications but different power ratings and output voltages are available.

The HLG-185H-24B also has a dimming function; this means that it can be used to change the light level on single-colour Flexi Strips. The HLG-185H-24B’s PWM dimming function also means that it can be driven by a DAP-04 DALI to PWM converter; a Flexi Strip installation can then become part of a larger DALI-controlled lighting scheme.

Figure 2 - Mean Well HLG-185H-24B 187W 24V IP67-rated LED power supply