LED modules run on low-voltage DC, usually 4.5 V or 5 V, and draw a lot of current. Each cabinet therefore carries one or more switching power supplies that turn mains AC into that low voltage. Getting the number of supplies right keeps the screen bright, stable and long-lived.
Start from the datasheet
Qiangli's datasheets give a ready-made sizing table for every module. Two examples:
| Power supply | Indoor Q1.5-52S Pro (max 6.6 A per module) | Outdoor Q4 front-service (max 9.5 A per module) |
|---|---|---|
| 40 A supply | 3 – 4 modules | 2 – 3 modules |
| 40 A PFC supply | 5 – 6 modules | 3 – 4 modules |
| 50 A supply | 5 – 6 modules | 3 – 4 modules |
| 80 A supply | 8 – 10 modules | 6 – 7 modules |
Every Qiangli module page on our site lists its own table under Electrical, and you can download the full datasheet there.
Leave headroom
Never load a supply to its full rating. Hangte, for example, recommends keeping about 30% margin above the real load for a longer service life, and mounting their slim supplies on an aluminium plate if they will run at full load continuously. Supplies that run hot at full load are a common cause of dark patches and early failures.
A worked example
Take a 960 × 960 mm outdoor cabinet holding 18 modules of 320 × 160 mm. If the datasheet says one 40 A supply drives 2 to 3 of those modules, you need between 6 and 9 supplies of 40 A per cabinet; using larger 60 A or 80 A supplies brings the count down. Always plan wiring so each supply feeds whole modules, never half a module.
Other things to check
- Voltage: match the module's input voltage (most here are DC 4.5 V ± 0.1 V).
- PFC: supplies with active power-factor correction, such as the Hangte LPA series, draw cleaner current from the mains, which matters on large screens.
- Earthing: the datasheets ask for the supply cases, cabinets and screen frame to be properly earthed.
See our LED power supplies or ask us to size the supplies for your screen.