| ??? 01/01/10 15:56 Modified: 01/01/10 15:59 Read: times |
#172096 - Two questions... Responding to: ???'s previous message |
Do you drive all the LEDs with the same current? This would explain, why the orange LEDs are a bit less bright than the green ones: http://www.8052.com/users/mahmood/sign.jpg
To which amount do you change the LED current to provide ambient light control? Mahmood said:
Shall I try Octopus wiring to the LEDs only power supply or Both LED and Drivers power supplies? That's not simple: You must route each signal and power line with the corresponding ground line very close nearby, to provide a current path for the ground return currents, without forming a loop. Only by this the inductances and corresponding voltage drops are small. But a bit more is needed to just put two wires together. The there-and-back conductors must be very close to each other. Another problem is, that these many cable pairs must not form loops either. So, what you need is a solid ground plane in your panel, a radio frequency plane over which you route all these cables, with very close distance to this ground plane. Connect all the many signal grounds of your driver boards to this big ground plane with shortest connections. This RF plane in combination with the steel grid provides a perfect shielding and the best chance of keeping the ground bounces low. Kai Klaas |
