Control 2 LEDs with 1 switch

Question

How can I control 2 LEDs?

Requirement is:

• Position 1: LED1 is ON
• Position 2: LED2 is ON
• Position 3: LED1 and LED2 both ON

Preferably using only 1 switch (not the DPDT ON-ON-ON switch).

Answer 1

A single-pole, 3-position rotary switch may be used.

Answer 2

here's one way: use the switch to bypass the LEDs.

^{simulate this circuit – Schematic created using CircuitLab}

Answer 3

Here is a way to do it with diodes and an on-off-on toggle switch with the center position 'off' and dedicated to D2 on.

Both D5 and D6 are optional but help even out the brightness. D6 helps match the brightness of D1 and D2 if they are both the same type and the resistors are the same. D5 helps match the brightness of the two situations in which D1 is 'on'.

^{simulate this circuit – Schematic created using CircuitLab}

Answer 4

A slightly different approach:

^{simulate this circuit – Schematic created using CircuitLab}

Another idea uses logic gates. I might show that as well, if I can design it. This would be best done with a PLD or a microcontroller.