Adding LEDs to PCBs without LED holes

[Photoelectric]

I know that my best option to adding LEDs to a compact keyboard would be getting something like a Poker II, which has a PCB that already supports LEDs.  However... I really like the arrow cluster and don't want to be without it.  There are backlit 75% keyboards, but I don't like them.  Leopold FC660M is really attractive to me in terms of the layout, but it has no LED support as far as I know.

Does anyone have an idea of how I could add LEDs to it?  I imagine I'd have to connect them with a string of thin copper wire, but I have no idea how I would manage it given that there's also a plate over the PCB and really not much room for the copper wire to go and not touch anything conductive on the PCB or the plate (though I could coat the plate with something extra nonconductive).

Can I do this mod or am I limited to something like EL wire?

[Sifo]

You can direct wire the LEDs if you drill holes into the pcb for them to sit in. Of course you'd still need the resistors and everything

[Photoelectric]

Eek, drilling the PCB...  I do have a good drill, but it'd be very dangerous work to drill 2 tiny holes right next to each other in a fairly thick PCB.  Don't know how brittle it would be either.

Why, Leopold!!  I'd have an ideal keyboard if it supported LEDs.

[tricheboars]

how do you plan on supplying power to the LEDs?

[Photoelectric]

Not sure--wiring it to the area where the mini USB cable plugs in along with some resistors along the way?

[StrikeEagleCC]

I agree that drilling is risky. There's a good chance that the holes would end up in an existing conductor. Is completely removing the switches from the PCB an option for you? If so, you could de-solder the switches and file two fine grooves in the bottom of the switch body from the LED holes to the edge. Then, cut the LED leads short and solder some 40 gauge wire to them. The wires would then sit in the groves between the switch and the PCB and you could route them wherever you wanted. Looking at my keyboard, it looks like it is doable, but labor intensive.

[mashby]

I too have been interested in this. I've come across two methods that might do the trick:

1. EL Wire - http://geekhack.org/index.php?topic=40872.0

2. Direct Wiring (but I can't find the post where I saw it)

[Photoelectric]

Yes, direct wiring is the only option, but as I said in the first post, I can't figure out how I could route them without touching any conductive surfaces.  Don't need to cut anything in the switches--there are already long side slits where the LEDs are inserted, in the bottom part of the housing so it would be under the plate. Pass an LED through the top of the switch and bend the ends sideways to come out of the front of the back of each switch.

It seems sort of doable.  I imagine it as follows:

- desolder all the switches
- separate them from the plate and the PCB
- mod switches as desired
- seat them onto the plate firmly
- insert LEDs and wire them.  Perhaps use coated copper wire to avoid contact with any metal on the PCB and the plate or else use liquid electrical tape to coat bare wires after they've been connected
- once the wiring is done, insert the PCB over the switch pins and solder the switches.

Some questions:
- love some pointers on good wiring to use for this.  I don't believe I can use any bare metal wire, unless liquid electrical tape dries quickly and is easy to use for this in practice
- Also are there any guides on how to connect the LEDs properly in terms of where to place resistors in the chain for keyboards? 
- Should there be one circuit for ALL of the LEDs?  One or more resistors to get to a proper value in series, and then the loop splitting to all of the LEDs, some in series, some in parallel by rows?
- And finally supplying power.  Where do I connect the ends of the LED circuit wires?  Find the +5V signal and ground locations on the main power hub area (say we're talking about a Filco with an internal connector, because I don't know what Leopold's power supply mini USB area looks like internally) and solder in corresponding wire ends to them?

[MOZ]

SMD Leds?

http://in.mouser.com/Optoelectronics/LED-Lighting/LED-Emitters/Standard-LEDs-SMD/_/N-b1bb1

[Photoelectric]

Er no, that's not what I'm looking for.  I need LEDs IN the switches under keycaps.  I don't even know how those could be added given there's no LED compatibility on the PCB, as stated.  Easier to do normal LEDs and use wire.

[domoaligato]

have you seen the new keycool 84?

http://mechanicalkeyboards.com/search.php?keyword=84&switch_id=ALL&size=ALL&man=30&key_plastic=ALL&backlit=ALL&interface=ALL&cord_length=ALL&usb_kro=ALL&ps2_kro=ALL&x=-1234&y=-318&in_stock=on

[Photoelectric]

What is new about it, sorry?  Also it's a 75% board.  But I do wonder if the PCB is the same between the backlit and non-backlit versions, allowing to add LEDs to the latter.

[domoaligato]

Sorry I was not sure if you had seen the layout. It seems a lot better then the race layout is all.

[Photoelectric]

No worries--thank you   I mentioned in the first post that I don't like the look of 75% keyboards (just a mess of 1x caps to my eyes).

[domoaligato]

I have an idea. I do not have a led to show but will try to demonstrate with this picture.

drill a tiny pin hole in the corner pillers where I am showing.

you should be able to then have enough of the led lead left on each side of the switch for the resister's.

[domoaligato]

the pin hole will go in the bottom of the triangle support potion showed here

[domoaligato]

this might be easier to see.

[domoaligato]

your led will have the leads bend in a T shape with the led sitting in the same position it normally would.
you might need to do this with slightly smaller led's so that the keycap doesn't bump the led when the keycap bottoms out.
not sure about the clearance because I have not tested it.

[yasuo]

buy sticker blacklight (glow in ther dark) )
or paint your plate w/ paint (glow in ther dark) )

[domoaligato]

I just thought about it for a few more moments and if you drill where I showed in the third pic and then put your bit through both holes and dig the bit down into the led area to drill a line as indicated in pic 1 you will be able to fit a larger led.


edit:

"- Should there be one circuit for ALL of the LEDs?  One or more resistors to get to a proper value in series, and then the loop splitting to all of the LEDs, some in series, some in parallel by rows?"

I would wire a matrix of led's and resisters and use a teensy 2.0 controller independently of the existing hardware.
mod the case to support the additional controller + usb plug

[ctrl]

Yes, direct wiring is the only option, but as I said in the first post, I can't figure out how I could route them without touching any conductive surfaces.  Don't need to cut anything in the switches--there are already long side slits where the LEDs are inserted, in the bottom part of the housing so it would be under the plate. Pass an LED through the top of the switch and bend the ends sideways to come out of the front of the back of each switch.

It seems sort of doable.  I imagine it as follows:

- desolder all the switches
- separate them from the plate and the PCB
- mod switches as desired
- seat them onto the plate firmly
- insert LEDs and wire them.  Perhaps use coated copper wire to avoid contact with any metal on the PCB and the plate or else use liquid electrical tape to coat bare wires after they've been connected
- once the wiring is done, insert the PCB over the switch pins and solder the switches.

Some questions:
- love some pointers on good wiring to use for this.  I don't believe I can use any bare metal wire, unless liquid electrical tape dries quickly and is easy to use for this in practice
- Also are there any guides on how to connect the LEDs properly in terms of where to place resistors in the chain for keyboards? 
- Should there be one circuit for ALL of the LEDs?  One or more resistors to get to a proper value in series, and then the loop splitting to all of the LEDs, some in series, some in parallel by rows?
- And finally supplying power.  Where do I connect the ends of the LED circuit wires?  Find the +5V signal and ground locations on the main power hub area (say we're talking about a Filco with an internal connector, because I don't know what Leopold's power supply mini USB area looks like internally) and solder in corresponding wire ends to them?

I agree that drilling is risky. There's a good chance that the holes would end up in an existing conductor. Is completely removing the switches from the PCB an option for you? If so, you could de-solder the switches and file two fine grooves in the bottom of the switch body from the LED holes to the edge. Then, cut the LED leads short and solder some 40 gauge wire to them. The wires would then sit in the groves between the switch and the PCB and you could route them wherever you wanted. Looking at my keyboard, it looks like it is doable, but labor intensive.

I know this is an old thread, but I'm wondering if anyone took pictures of how they modded the switches?

I'll have a switch with in-built place for a LED, but the LED leads won't align with the holes in the PCB. Would filing the switch body and wiring the LED leads solve the issue? How would I file the switch body?