| ??? 02/11/09 09:36 Read: times |
#162271 - LED current - sweeping generalisation Responding to: ???'s previous message |
Kai Klaas said:
... continuously driving a standard LED a current limiting resistor of 15 Ohm, as mentioned in one of your previous posts, is way too small! We don't know that it is a "standard" LED. High-Power LEDs are widely available today that are easily capable of handling well in excess of 80mA. 15 Ohm makes only sense in a multiplexed system, or when your LED is only turned-on during a small period of time Or if it's a suitable, high-power LED. Whatever the case, of course, it must be verified against the specifications detailed in the Datasheet for the specific LED being used. So, before you actually put this 15 Ohm into your circuit, first make sure that the code of micro is running properly This is still very good advice! Driving such high-power devices brings special issues all of its own - so it really isn't a novice project. You should start with a simple, low-power matrix. Once you have that working, then you can move on to the special considerations of a high-power version - not least of which is an adequate power supply... |
