| ??? 08/21/05 05:18 Read: times |
#99757 - Spec for LED Responding to: ???'s previous message |
Dear Jose,
After I read the spec for my LEDs, the min forward voltage is 1.3 for red in 20mA, 2.5 for green and blue in 20mA. And max. voltage is 2.4V for red and 3.9 for green and blue. And I try this value in experiment, find that when 1.3V and 2.5V, the LEDs will not light up. And I continuous test them and find the greatest brightness occurs when red is in 2.1V with 0.12A and Green and Blue also at 3.6V with 0.12A with no resistor in series. Hence if I need to pull the LED in the greatest bright, I nearly need 0.25A for an LED with around 3.6V in series with no resistor for green and blue and with 10Ohms resistor in series with red. Also, I find the max luminous for red is 2700, blue is 4500 and green is also 4500. Is these luminous for the LEDs are Ok for the outdoor lighting? If not, would you give some suggestion for the improvement of the LEDs. Thankyou very much. |
| Topic | Author | Date |
| Questionn - Not even brightness for LEDs | 01/01/70 00:00 | |
| Sounds like you've answered the question | 01/01/70 00:00 | |
| What minizium change I need | 01/01/70 00:00 | |
| Test some things | 01/01/70 00:00 | |
| Test | 01/01/70 00:00 | |
| Try PNP instead of NPN | 01/01/70 00:00 | |
| Both method | 01/01/70 00:00 | |
| Increase the voltage accross the load | 01/01/70 00:00 | |
| even brightness... | 01/01/70 00:00 | |
| Spec for LED | 01/01/70 00:00 | |
| something is wrong... | 01/01/70 00:00 | |
| RGB LED's Luminous | 01/01/70 00:00 | |
| even considering voltage will get you in | 01/01/70 00:00 | |
| Explain more | 01/01/70 00:00 | |
| simple, drop the multiplexing | 01/01/70 00:00 | |
| Will this work | 01/01/70 00:00 | |
| Erik says | 01/01/70 00:00 | |
| this will | 01/01/70 00:00 | |
| Can I use UDN2891a | 01/01/70 00:00 | |
| can't say | 01/01/70 00:00 | |
| probably means 2981 | 01/01/70 00:00 | |
if so, you just don't get it do you | 01/01/70 00:00 | |
| why would you do that ? | 01/01/70 00:00 |