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I couldn't find the switch I am looking for, but the most closest one I found is this.

It has 2 LEDs, and I would like to utilize the LEDs to display the status of the device. For my case the colors are green and red. This is what I mean:

enter image description here

The boxes above represent a period of time and the colours inside is the LED being on/off for that period of time.

So essentially the actual switch will just be a switch and have the task - to turn on or off the device but the inbuilt LEDs will be independent of the switch and just represent the status of the device.

Q1: Is this possible with the aforementioned switch? Alternatively is there a 'hack' to utilize the switch in this way?

Q2: Is there manufactured switches designed for such tasks - and what type of switches are they?

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  • \$\begingroup\$ Can't seem to find the datasheet for the switch on that page. \$\endgroup\$ Sep 17, 2015 at 3:34
  • \$\begingroup\$ @NickAlexeev Tehcnical Information \$\endgroup\$
    – 3kstc
    Sep 17, 2015 at 3:54
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    \$\begingroup\$ The switch leds are independent of the switch itself. In order to implement an the pattern you would use a microcontroller to toggle the leds. \$\endgroup\$
    – crasic
    Sep 17, 2015 at 4:21
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    \$\begingroup\$ I would recommend finding a manufacturer that provides a real datasheet \$\endgroup\$
    – crasic
    Sep 17, 2015 at 4:21
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    \$\begingroup\$ @3kstc That's not a datasheet, which brings us to the cardinal rule: No datasheet ⇒ No sale \$\endgroup\$ Sep 17, 2015 at 4:23

1 Answer 1

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I guess that I don't understand your problem.

You have a switch that has two LEDs built into it. You can control those LEDs any way that you want.

Because I see only 3 leads for the LED connections, you will have to find out whether the LEDs are wired Common Anode or Common Cathode. That is: are the (+) leads of the two LEDs connected to one pin or are the (-) leads connected to one pin.

As the comments mention, you will drive the LEDs from your microcontroller. Depending upon the output voltage and current from the microcontroller, you may need an interposing transistor or MOSFET to allow running the LED from a different supply rail from the microcontroller.

You need to find out the recommended forward current for each of the LEDs. Do note that the forward voltage for each LED may be different from the other LED - and the recommended forward current may also be different for each LED. Either consult the datasheet or do some simple experimentation to find out.

In general, older LEDs run at around 20 mA while newer, more modern (more efficient) LEDs can run from 1 mA or even less.

Red LEDs usually have a forward voltage drop near 1.7 Vdc and older Yellow or Green LEDs tend to drop about 2.1 Vdc. Newer Green or Blue or White LEDs usually drop about 3.2 Vdc.

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  • \$\begingroup\$ Those leds are meant for 12V (meaning they likely [hopefully] have an apropos resistor sized for that). \$\endgroup\$
    – Passerby
    Sep 17, 2015 at 7:03

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