Illuminated Rocker Switch Voltage Conversion

by Onyx Ibex in Circuits > LEDs

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Illuminated Rocker Switch Voltage Conversion

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I am working on building a electric drift trike and wanted a switch for the electronics. Unfortunately, most DC switches around 48V tend to be either costly or not at all what I wanted (meaning did not include an internal light). I had this illuminated blue rocker switch sitting around but it was designed for 125V for the internal light. In this instructable I will show how I changed the 125V light to a 48V LED AND re-assembled it without breaking anything :)

This is a short ible and hopefully someone may find it useful just to know they need not fear to pull one of these apart and that it can be tailored to any voltage desired.

Breaking Before Making

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The first step was just to figure out how to pull it apart so I could get at the internals. I found that using tweezers I was able to pry the top blue rocker out of the black case while also pushing in the side tabs (on the long edge side, the holes where the switch snaps into). Doing so caused the whole thing to spring apart on me, so I recommend you try to be more careful than I was!

Once I have all the pieces in front of me, I was able to match it to the datasheet (2nd pic). In the lower right of the datasheet image you can see that contacts 2 and 3 are where the light was connected. I cut out the 150k ohm resistor and the light and discarded them. The light will not did not work at the voltage I wanted anyways (it should have based on 125V through a 150kohm resistor though, not sure why it didn't). I swapped in a blue 1206 SMD LED (3.2-3.4V). I aimed to run 5mA through the LED (could have done more) so I grabbed a fresh 10k ohm resistor as well. You can design the switch to illuminate at whatever voltage you want, just match the resistor accordingly.

I would one leg of the resistor in a similar fashion to the way the leg was wrapped around the rocker before I cut it out. See pic 4 for clarification because it is too hard to describe. I then trimmed the other leg of the resistor very short. It would then be soldered to the LED. The leg that was trimmed off was then used as the other pin for the LED and was wrapped around the other end of the rocker (see pics).

Re-assembly

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After soldering in the LED and resistor and bending their wires around back to how it looked when I took it apart, it was time to put it all back together. The middle black spring was put back in the rocker in the central hole where it would press against the leg of the resistor. This spring will eventually press against the small metal piece we put into the bottom of the case (pic 5 and 6).

Then the blue rocker cover can be put back onto the rocker (pic 2).

Then the small metal piece (pic 5 and 6) can be slid into grooves (pic 6) in the center of the black bottom case. Carefully lower the rocker down while aligning the black spring over the tip of the small metal piece while simultaneously aligning the spring that stayed connected in the bottom case into the other hole on the rocker switch. Press shut firmly until the blue top snaps / locks into the holes on the black bottom case.

Done!

If you picked the same resistor value as me you can test it out with a 48V source to make sure it turns on. Notice that it isn't connected to the switching line but rather is powered externally over the 3rd pin to the common central pin. You can power the LED at any voltage you design it for, just make sure to match the resistor accordingly!