I'm going to make some LED circuits, but I'm not sure if it will work.
The problem is that I want to use Red and Blue leds, but they have different drop voltage. Will this circuit work?
Simple parallel SMD LED circuit(need help)
ledparallelsurface-mountvoltage
Related Solutions
The big problem is that you didn't draw the schematic properly. A good schematic always makes the things clear:
simulate this circuit – Schematic created using CircuitLab
The current is \$I = \frac{U}{I}\$
I0 = I1+I2
I0 = (5V-2.065V)/270 = 10.87037037mA
I1 = (2.065V - 1.863V)/100 = 2.02mA
I2 = I0 - I1 = 8.85037037mA
simulate this circuit – Schematic created using CircuitLab
The red led has 1.4V forward voltage drop while the green one has 2.2V. When the red one is on, the green one will not have enough voltage drop and will be very dim.
If you want to turn off the green led completely off, you can use a MOSFET switch like this.
Best Answer
No, it won't work, or at least not very well.
But not because you have red and blue LEDs.
It won't work because even LEDs with the same color will have slightly different forward voltages, especially if they are at (even slightly) different temperatures.
So your three blue LEDs in parallel won't light up equally, and your three red LEDs in parallel won't light up equally. Possibly the difference in characteristics will even be enough to damage the LEDs.
The better solution is just to use a separate resistor for each LED.
simulate this circuit – Schematic created using CircuitLab
Or, if you have a higher-value voltage source available, place all the LEDs of the same color in series so that they are sure to all get the same current.