Application Note – Redundant Power Supply for LED Display Panels

14 April 2020

The development of high-brightness and high-resolution LED display panels means they are widely favoured by most advertising companies and property managers.  

The latest small-pitch LED display panels offer higher clarity and resolution to achieve better graphics, images, and videos. 

The range of applications for LED display panels is ever expanding, especially in theatres, large-scale live performance venues, concert halls, and for video conferencing. 

Most LED display panels use a single power supply.  

If the power supply fails, then the LED panel stops working. This can result in the advertiser receiving a complaint, or compensation request from their customer, as the adverts are not being displayed in accordance with the customer’s contract.  

MEAN WELL has a solution to this problem. 

Using the redundant function on the UHP series power supplies, you can connect two power supplies in parallel, so that one takes over, should the other fail. 

MEAN WELL UHP-200R Redundant Power Supply for LED Sign Panels

Typically in a redundant system, you would connect two power supplies in series with diodes fitted across the output of each power supply. This is to prevent reverse voltage across the power supplies. 

Wiring diagram redundant power supplies for LED displays in series with diodes

Some form of external controller is required to activate the back-up power supply, should the main unit fail 

The MEAN WELL UHP series power supplies are available with a redundancy function. This is available on the following versions: 

Output Voltages Available
Power Output Range
UHP-200R  3.3V, 4.2V, 5V, 12V. 15V, 24V, 36V, 48V  132W ~ 201.6W
UHP-350R  3.3V, 4.2V, 5V, 12V. 15V, 24V, 36V, 48V  198W ~ 351W 
UHP-500R  4.2V, 5V, 12V. 15V, 24V, 36V, 48V  336W ~ 5106W 

The current sharing function allows two power supplies to be connected in parallel, as per the below diagram: 

Wiring diagram MEAN WELL UHP-200R redundant power supplies for LED display panels

When one of the power supplies stops working, the other is automatically enabled. No external controller is required. 

A DC OK output signal allows you to monitor the power supplies, so that a failed unit can be sourced whilst the redundant unit is supplying power to the LED panel. 

Another useful feature of the UHP series power supplies is their slimline design, with a low profile.  

This means it can be incorporated into LED display panels, where there is limited space. 

Remember to consult the data sheet to establish the minimum heatsink / surface area requirements for adequate cooling.  
Please do not hesitate to contact MEAN WELL Australia if you would like further information on the UHP series power supplies with redundant operation.