| ??? 03/28/07 07:32 Read: times |
#136000 - What I've noticed Responding to: ???'s previous message |
As for traffic lights, as someone else mentioned, the green leds get hotter, so that might be causing cracking of the solder joint due to thermal stress. Another bizarre effect I've seen is vibration affecting leds only in particular positions. This was seen on a large display board I built that used 2" led clusters. The little circuit board inside was single sided and the solder joints were cracking. The clusters were replaced with higher efficiency leds on double sided pcbs. Problem went away. you might want to find out who fixes the traffic lights and get a failed unit to find out what it died from. Fair chance it is one of the above problems. I've yet to see a led actually fail internally except due to over current. |
| Topic | Author | Date |
| Do green LEDs have worse reliability? | 01/01/70 00:00 | |
| Seems so... | 01/01/70 00:00 | |
| Hhm... | 01/01/70 00:00 | |
| My german isnt that good but..... | 01/01/70 00:00 | |
| various reasons | 01/01/70 00:00 | |
| then again... | 01/01/70 00:00 | |
| what I have seen ... | 01/01/70 00:00 | |
| What I've noticed | 01/01/70 00:00 | |
| get a failed unit | 01/01/70 00:00 | |
| Designing for failure | 01/01/70 00:00 | |
| Nothing new under the sun | 01/01/70 00:00 | |
And can your contacts confirm or deny... | 01/01/70 00:00 | |
| Government rules | 01/01/70 00:00 |