Lighting – How to connect a Juno LED light to a switch when the light receives power first

The easiest way to run an LED off of 120VAC is to use an LED that's already designed for 120VAC, like a 120VAC LED Panel light. They come in a wide variety of sizes, colors, and form factors.

(Photos from Digikey's catalog).

Just keep in mind that 120VAC is dangerous, and if you're not actually going to panel mount them where only the front of the LED is exposed to the user with the rest of the LED shielded by an insulating or grounded panel, make sure that you keep them safely isolated so the user can't inadvertently come into contact with the back side of the LED housing or wires.

You have all the right parts.

If you didn't want to dim them, this would be simple - just parallel them all to the power supply.

Since you do want to dim them, you need to think about how dimming works. These products are generally PWM dimmers which pulse the LEDs on and off, and the percentage of "on" time decides the brightness. LED amplifiers take this as an input, and pulse their outputs exactly the same. So, the output of the PWM dimmer can be "power" to LED strips, "signal" to amplifiers, or a little of both.

This particular amplifier is 192W, but it's also RGB, which means it's 3 channels (red, green, blue) at apparently 64W per channel. I'd send the same (monochrome) PWM signal to all three RGB inputs, and drive white LED strips off each output.

• 120v power to your power supply.

• 12v power to both the dimmer and the amplifier.

• Dimmer output split to all 3 inputs on the RGB amplifier.

• Dimmer output also drives two LED strips, in parallel.

• Each of the RGB outputs of the amplifier drives two LED strips, in parallel.

Alternate which strips are powered by which source, so the 8 strips are powered something like RGDBRDGB. That way, if one channel fails, the strips which fail will be some distance apart and it won't leave such an obvious dead spot on your panel.

The common Chinese dimmers have a limited dynamic range, i.e. they can't go "very dim", they just turn off if you go below a certain brightness. This can be annoying. For this reason, I suggest adding a cutout switch on the signal to the amplifier. That will disable its 6 LED strips, leaving the 2 driven directly off the dimmer. That is why I suggest distributing them strategically so they can do a reasonable job lighting the panel alone. This is a soft limit of cheap Chinese dimmers - if you are creating that PWM signal yourself using an Arduino or whatnot, you can go as dim as you care to. Just try to keep the pulse frequency as high as possible, certainly over 200Hz, so it isn't visible to the naked eye.