| ??? 08/24/05 11:48 Read: times |
#99971 - Erik says Responding to: ???'s previous message |
Mary Joany said:
THankyou again for your reply. If I change my circuit to simple parallel LEDs, then use 3V to drive Red in series with 1.8Ohm. and use 4V to drive Blue and green LED in 2 separate circuit with collect to 1Ohm resistors in 6W is it Ok? It will be terrible. There is no way that your current sources will be stiff enough to cope with the variations of LED performance with age and temperature. Like Erik says you need proper Constant Current drivers. Steve |
| 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 |