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High/Low light LED switch Answered

I recently purchase some 3528 300p LED Strip Light so that I can make some under cabinet
lighting. I wanted to make my own because I believe I can to it for a much better price
and learn something in the process rather than buying an LED light set from a big box

I have a 3 position rocker switch Off/high/low. If possible I would like to use the LED
lights in a High/Low configuration. From what I read they make PWM modules that control
the LED making them appear to be dimmable, but I do not want to use one of these devices.

For the low setting I was considering wiring in a POT or an inline resistor to drop the
Voltage to the LED's. On second thought I suspect that this would not work and if I drop
the voltage too low this would result in inoperable LED's. By the way I would not be opposed using an inline resistor if this is a good way to reduce the light level

Is there some cheap electronic component that will produce or simulate an approximate 50%
PWM that I can wire inline with the switch, in effect producing a low lighting mode? I
am not interested in using a variable PWM control, I just want to achieve a switchable
high/low lighting. I am not familiar with components and I hope you could suggest a few
ideas for my project.

Some details: The led strip will be ~11 linear ft using 12VDC and about 40W of



8 years ago

I'm always in favor of keeping it as simple as possible. Instead of trying to dim the LEDs, what if one setting only lit every other LED?


Answer 8 years ago

The LEDs are already pre-wired in series. I bought a pre-wired LED strip. It has 300 LEDS and I will only be using ~200 of these under the cabinet. Otherwise a good idea.


8 years ago

See what effect putting them in series and parallel has. Failing that, put a circuit like this in, and wire a fixed resistor where the pot is, switched by your hi-lo-off switch.

trimmable current source.JPG