Best Of Keystone Customs announces Angled numberboards for your SW Diesels

[peteski]

Ok, so 4 wires go down the hole. Yes, if the wire is thin enough then that won't be a problem.

[Lemosteam]

@peteski No only the two as shown in the last pic.  As you can see in the first pic, both leads of one LED have been cut really short and soldered part way down the two leads from the other (see the solder joints.  the other leads are left long and fed through the hole in the bottom.  I think it "in series"???

[Lemosteam]

@tehachapifan , these are the new legs at 45 degrees: 

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[peteski]

No only the two as shown in the last pic.

So the solder joint will be inside the number board housing?  The wires of one of the LEDs will have to be pretty short to do that and the solder joint will also have to be pretty darn close to the LED. There isn't much room inside the enclosure to tuck all the extra length of wire in there.

That is a parallel connection. Series is like Christmas lights where there is only one wire between individual lights, Then the ends of the string get hooked up to the power source.

[Lemosteam]

Bingo!

OH well, I had a 50/50 chance...

[peteski]

Bingo!

OH well, I had a 50/50 chance...

LOL!

I still want to see you ball up those extra wires and stuff them in that tiny cavity.    But since you designed these for others, you probably won't have to attempt that.

[Lemosteam]

I might buy some just to try it!

[tehachapifan]

Changes look great! Thanks for doing that!

[tom mann]

I added the 'Best of' prefix to this thread because it's a great example of so many positive things.

[Lemosteam]

would recommend that you wire the LEDs in series.

-Dave

@railnerd , Dave, sorry I missed this comment.  For my edification, can you explain why in series is better than what I have shown above (parallel)?

Also, @peteski 's center image would be simple to do as well, is more elegant, and can still be done using pre-wired LED's.  Does that schematic reduce power going to the second LED because it has to go through the first one?  just curious if that is a factor for even illumination.

[tehachapifan]

That second example in Peteski's examples is how I wired the numberboards in my SW1500 bashes (one 0603 SMD LED per board) in addition to using a strong resistor and turning the brightness CV way down. I wanted them to be barely visible in normal (simulated-daytime) lighting anyway and have a soft glow with the lights off. They all look good but there is one loco that has one side that is a little brighter than the other using this wiring, which is fine with me as it looks like maybe a bulb is out in the housing or something. The others using the same wiring look nice and even.

....all this said, I will probably only install one LED per board in these anyway. I don't notice a "hot spot" issue in my SW1500's, so I'm not expecting an issue here. That said, the LED's will be sitting closer to the window surface in these than in my 1500's.

[peteski]

@railnerd , Dave, sorry I missed this comment.  For my edification, can you explain why in series is better than what I have shown above (parallel)?

Also, @peteski 's center image would be simple to do as well, is more elegant, and can still be done using pre-wired LED's.  Does that schematic reduce power going to the second LED because it has to go through the first one?  just curious if that is a factor for even illumination.

When connecting 2 identical electronic devices in parallel then the voltage  needed for operation remains the same as for a single device, but the current consumption will double.
When connecting such devices in series (which is what you are asking for), the voltage needed for operation is doubled, but the total current need remains the same as for a single device.

What doesn't change is the total power dissipated by those devices (since in both circuits each device ends up being supplied with the same voltage and consumes the same amount of current).  Power dissipation (in DC) is calculated as voltage times current. All of these are the very basic laws of electronics.

So in the series-connected pair of LEDs (where each LED needs (drops) around 3V across it (in order for it to illuminate) you will need at least 6V to power the circuit.   We also always need to add the current limiting resistor in series with the LED circuit. That will limit the current and by definition part of the supply voltage will be dropped across it.

[railnerd]

@railnerd , Dave, sorry I missed this comment.  For my edification, can you explain why in series is better than what I have shown above (parallel)?

1) One resistor, not two
2) In parallel configuration, only one LED may be lit unless you add a resistor per LED to ensure current flows through both LEDs.

[peteski]

1) One resistor, not two
2) In parallel configuration, only one LED may be lit unless you add a resistor per LED to ensure current flows through both LEDs.

1) Series-connection also results in simpler wiring.
2) If the LEDs are identical you can use a single resistor in series with the pair of parallel-connected LEDs. Theoretically each of the LEDs will carry half of the total circuit current. But personally I do not endorse this method (like railnerd I prefer a separate resistor in each LED chain).

[tehachapifan]

Rec'd my revised boards today and they look great (thanks, John)! The size difference is definitely noticeable. I have them soaking now and my SP SW1200 is almost ready for paint. Still need to order some 0402 SMD's to illuminate them.