LED components can be designed and selected to offer reliability and long life. However it is also critical to consider the lifetime of the power supply unit, can this support and match the lifetime of the LED? Many LED users are unaware of the de-facto industry standard for driver failure: 0.2% per 1000 hours. So how do you build this into design considerations and product life expectations?
The three key factors affecting driver performance are:
- Electronic product reliability
- Key component lifetime
Electronic product reliability
Electronic products can be extremely reliable but ‘you get what you pay for’. In terms of value for money if you shift from price to performance and understand that the current industry rate is 0.2% per 1000 hours de-facto standard for lighting electronics, the quality of the electronic products you select and purchase has a direct impact on product life and LED performance. Always check manufacturer’s technical specifications for driver lifetime value and failure rates.
Key component lifetime
The lifetime of a driver is determined by the lifetime of its individual components. Factors affecting key component lifetime include:
- Electrolytic capacitors: these components have a temperature-related lifetime; generally their lifetime halves with every 10°C increase in temperature
- Freewheel diodes: diodes can fail due to high voltage stresses and other factors
- Bridge rectifiers: bridges are permanently ‘on’ so are continually dissipating energy
- Optocouplers: optocouplers can fail for a variety of reasons
Failure in any one can cause the lights to go out, flickering and EMC non-compliance etc.
Ineffective or faulty soldering can cause a driver/PSU to fail. Causes of poor soldering include low operator skill, poorly controlled manufacturing processes and quality assurance procedures. Again this can impact on a driver by causing the lights to go out. Prevention is pretty simple: control your manufacturing to the Electronic Industry’s ‘bible’ of soldering IPX-A-610-E!
How can I prevent LED driver/PSU failure?
Here’s a check list to help prevent driver/PSU failure:
- Understand that driver quality and life impacts on the performance and longevity of the LED module
- Always check that the driver manufacturer’s technical specifications for lifetime values and failure rates
- Be aware of the industry failure rate
- Educate and support customers, especially those new to LED lighting
- Observe and follow LED manufacturer’s specifications
- Ensure control manufacturing processes and policies are in place
- In summary LED lighting can be extremely reliable, but you need to be profoundly aware of all the issues. A good knowledge of potential LED failures and preventative measures will help to engineer and manufacture high quality and reliable LED products.