I am helping to build a costume prop that has four LEDs lights on it (1 white and 3 amber).
This device is worn on the wrist, so space for power is limited- a 9V battery or something that will fit in that space will need to power the four lights.
The device would work on a 4-position rotary switch. Here is how it needs to function:
position 1: off
position 2: white light on and left yellow light on
position 3: white light on and center yellow light on
position 4: white light on and right yellow light on
My long-ago electrical experience tells me that this should be pretty simple, but I just don't recall enough to make this work correctly. I also wonder whether the LEDs needs any circuit help since one of our folks only managed to burn them out connecting directly to a 9V.
UPDATED
Thanks for the feedback WhatRoughBeast and Sphero Pefhany! I appreciate the LiPo suggestion and safety feedback.
I'll take a closer look at the circuit diagram- it looks helpful. I reckon I'll need to do calculations on the resistors now that I have LEDs in hand.
There are more specifics for this case if any of y'all are still following this…
The rotary switch is a 3-pole 4-position switch. The 3 poles (labeled A,B,C) are in center of the switch, with 12 posts (labeled 1-12) in a ring around them.
The LEDs are:
white- Vf 4.1V max, If 25mA max, Vr 4V max, Pd 120mW max, Iv 4000mcd Typ
amber- Vf 2.4V max, If 25mA max, Vr 5V max, Pd 100mW max, Iv 5500mcd Typ
Thanks again for the help!
Best Answer
This should do it. SW1..SW3 are the contacts for positions 2,3,4.
R1 to R3 control the brightness of D1-D3 yellow LEDs, if you increase them also increase R4 proportionally.
R5 controls the brightness of the white LED.
simulate this circuit – Schematic created using CircuitLab
If you have a double pole rotary switch rather than a single pole, you can lose the transistor and R4 and just tie the second set of contacts to R5 to turn the white LED on whenever the switch is not in the 'off' position.