Use two resistors per circuit, between the last junction point and the LED or between the LED and the R and N leads, then you can adjust the resistance separately for the red and green LEDs.
The dashed line box suggests the two LEDs are part of a single package. To reduce the green LED's brightness, add a resistor in series between the green LED's upper terminal and the upper wire. If both LEDs are on at the same time, which is unlikely, as they have different operating voltages, that will also make the red LED brighter, because it will get more of the shared current.
As drawn, with the top and bottom wires extending, possibly to more LEDs, perhaps to something else, it's not a good idea to put the resistor in the top common supply wire, or pulse it instead of switching it continually to ground, either of which is another way to reduce the brightness of the green LED.
Of course. Simply add yet another resistor in series with each green LED.
BYW ¡ your simple circuit abuses the reverse voltage limit spec of each LED when it is supposedly off. Yes, the current is limited when/if reverse current does flow but it does cause increased power dissipation and a shorter lifetime.
Don V's BYW (BTW?) gives one of the reasons I put 1N4148 or 1N4150 signal diodes in series with the LEDs on my RR. Mine are multiplexed, so spend 7/8 or their time actively driven in the reverse direction.?
The diodes block the reverse voltage and current, reducing the loads on the drivers and any dimly glowing LEDs that are supposed to be off, glowing because of current leaking through reverse biased LEDs. Some people question whether this is possible, but I had the problem and the diodes fixed it.
When LEDs are scattered around the layout, whether on panels or in signal heads, or anywhere, I learned the hard way that they sometimes fail from voltage transients. To prevent that, I also put a reverse biased signal diode in parallel with each LED. Problem solved. I'm not aware of anyone else reporting that problem. YMMV.
On Sep 27, 2023 6:00 AM, Don Weigt <dweigt47@...> wrote:
Don V's BYW (BTW?) gives one of the reasons I put 1N4148 or 1N4150 signal diodes in series with the LEDs on my RR. Mine are multiplexed, so spend 7/8 or their time actively driven in the reverse direction.?
The diodes block the reverse voltage and current, reducing the loads on the drivers and any dimly glowing LEDs that are supposed to be off, glowing because of current leaking through reverse biased LEDs. Some people question whether this is possible, but I had the problem and the diodes fixed it.
When LEDs are scattered around the layout, whether on panels or in signal heads, or anywhere, I learned the hard way that they sometimes fail from voltage transients. To prevent that, I also put a reverse biased signal diode in parallel with each LED. Problem solved. I'm not aware of anyone else reporting that problem. YMMV.
Tim