LED-tipped toggle switch wiring

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P-Lay

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Hi all. I was looking through McMaster for some toggle switches and ran across some LED-tipped mini switches that I thought would be cool to integrate into a brew rig. The instructions state: "Include an extra set of solder-lug connections for powering the LED, which requires 20 mA @ 2.1 VDC." McMaster part# 7157K24 through 7157K27.

I was wondering if anyone knew how to wire these things up. It seems different than just wiring an LED in-line with the switched power line. Perhaps someone has a wiring diagram. Thanks.
 
So the LED is powered by a separate power supply and not a "knocked down" voltage from the line it's switching? That makes sense. I guess that means it has a separate internal switch to light the LED when the switch is active.
 
I don't know a lot about electronics, but what triggers the LED to go on? If it is unrelated to the power flowing through the 110/120 side of the switch then it may not be giving a true indicator of being ON.

Does that make sense?
 
Judging from the number of terminals each switch has...it appears that the statement: "Include an extra set of solder-lug connections for powering the LED, which requires 20 mA @ 2.1 VDC." should actually have an 's' at the end of the word 'Include'. That is...the switch already has the terminals for the LED. That's why the SPDT has 5 terminals (usually would be 3) and the DPDT has 8 (usually would be 6). That may have been obvious to some but the lack of that letter 's' threw me at first.

I don't know if those two terminals for the LED are switched but maybe they are. I know some similar-purpose switches I've used do not switch the terminals for the light.

If the LED terminals are switched in the switch then it's duck soup.

If the LED terminals are NOT switched by the switch then an easy way to illustrate it would be to use the DPDT ON-ON (i.e. 2 position) switch...which is basically two independant SPDT switches activated by the same switch. So one set of 3 terminals would be for switching the actual item you want to switch (like a pump) and the other set of 3 terminals would be for switching the power to the LED. The power for the LED would come from a walwart like BobbyM suggested (you could buy a transformer, voltage regulator, and rectifier, and smoothing caps and build your own but...buying a walwart is easier:)).

If the voltage to the LED is too high you can just put a resistor in series with the LED and that will knock it down (or use a potentiometer to adjust that resistance for a 'Brightness' control). You may have to piddle with a fixed resistance to get the brightness you want (and avoid burning up the LED).
 
Awesome. I would have never thought to use the DPDT to switch the LED. Good to know.
 
Here is a solution that will cost you $0.81. It will work with a SPST switch also if you don't want to switch both neutral and hot.

switch.jpg
 
That's what I was thinking about at first. How would you wire the diode and resistor into the switch? Would you just solder the connections and then use heat-shrink tubing around them?
 
I don't see what the point would be of including an LED on a switch, unless it was a switched LED.

I would try it out by hooking up the power lines directly to the LED and wiring the switch as normal (using the same power source as the LED), and if the LED is always on, it's easy enough so the switch is in series with the LED.
 
It is a switched LED but they don't operate on 120v AC which is what I assume the OP is looking to switch. They also have ones that glow red while the switch is off and green when on. Those are pretty cool.
 
That's what I was thinking about at first. How would you wire the diode and resistor into the switch? Would you just solder the connections and then use heat-shrink tubing around them?

Why not, this is not the first time I have done this. BTW, in my diagram if the switch is turned off the LED is not lit. Turn it on, it lights. All it is, is a diode to rectify the 120 VAC into DC and a resistor to drop the voltage to 2.1 VDC and limit the current through the LED to 20 miliamps.
 
I don't see what the point would be of including an LED on a switch, unless it was a switched LED.

I would try it out by hooking up the power lines directly to the LED and wiring the switch as normal (using the same power source as the LED), and if the LED is always on, it's easy enough so the switch is in series with the LED.

You will blow the piss out of the LED. If you look below the LED is only rated for 2.1 Volts DC and 20 miliamps. Not 120 Volts AC direct. Sheesh....Extremely bad advice:mad:

The instructions state: "Include an extra set of solder-lug connections for powering the LED, which requires 20 mA @ 2.1 VDC."
 
I'm kind of resurrecting an old thread.....but wouldn't the heat given off by the resistor be kind of a lot?
 
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