| ??? 02/17/07 16:57 Read: times |
#133176 - 7 segment LED question, "light crosstalk" |
While slightly off topic, this project is 8051 based. I have been using the MAN3940A LED from Qualtech/Fairchild/God_Knows_who_now. In past years the quality has been acceptable, but when Fairchild took over the units started to exhibit bleed-over from lit segments to non-lit segments. So a 3 would look a lot like an 8, etc. I powered some units up with DC to make sure it wasn't a multiplexing issue, and there is a lot of variability in the units.
I tried a few samples from other mfr's thinking I would switch over, and the samples (Lumex and Kingbright) exhibited the same symptom (although less pronounced). The QT part is dimensionally unique, it is lower profile than the pin-compatible units from the other mfr's. Before I redo the PCB to accept the other parts, I want to make sure that there isn't a better way. So, what are the experiences you guys have? Thanks guys! Bob |
| Topic | Author | Date |
| 7 segment LED question, "light crosstalk" | 01/01/70 00:00 | |
| Filters? | 01/01/70 00:00 | |
| I have one | 01/01/70 00:00 | |
| did you try decreasing LEDs intensity? | 01/01/70 00:00 | |
| Yes, I decreased the intensity, | 01/01/70 00:00 | |
| Optical bleed-over? Or... | 01/01/70 00:00 | |
| Custom Display | 01/01/70 00:00 | |
| Display Filters. | 01/01/70 00:00 | |
| Filter | 01/01/70 00:00 | |
| just to make sure | 01/01/70 00:00 | |
| Exactly! | 01/01/70 00:00 | |
Understood, good point. | 01/01/70 00:00 | |
| Nice, but... | 01/01/70 00:00 |