Bang Good Power Supply LEDs

[jakejm79]

Quick question:

The Power, Charging and Charged LED spots are specced has Blue, Red and Green, I assume that is because the PCB already constains resistors for those relevant colors.
i.e. I just need to solder bare LEDs to the spots and I could substitute White for Blue or Yellow for Green, but substituting White for Red could cause an issue right?

[VeteranGamer]

Quick question:

The Power, Charging and Charged LED spots are specced has Blue, Red and Green, I assume that is because the PCB already constains resistors for those relevant colors.
i.e. I just need to solder bare LEDs to the spots and I could substitute White for Blue or Yellow for Green, but substituting White for Red could cause an issue right?

i've always added resistor to the led (allows me to control how bright they are)....
as i also doubt that they would have gone to the length of adding resistors (especially for the different colours)
and then depending on the size you might add, things could also change....

besides you can add what ever colour you want.....




one thing to note, even if they haven't added resistors for the led (which i doubt they have, looking at the board)
i think the led are powered by the battery anyway which is 3.7v....
in most cases (depending on the led) you might not even need to add a resistor.....


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[jakejm79]

Thank you for your insight, the only reason I asked is because they appear to specify colors for the various positions. Surely if they were all fed the same signal (in terms of voltage and current) then there would be no color requirement. It also looks like R4 (Green) and R9 (Blue) are connected directly to where the LEDs would go, I can't tell for the Red LED maybe R14? But it also looks like it shares it common + with LED0, I wonder what color LED0 is, if red then quite possibly there is already a resistor in that circuit. Also the PCB appears to be silkscreened and drilled to directly accept a LED I'd imagine they'd have pads rather than through holes if you were meant to add your own LED circuitry (i.e. array and resistor) but they went to the extra expense to drill holes.

[VeteranGamer]

Thank you for your insight, the only reason I asked is because they appear to specify colors for the various positions. Surely if they were all fed the same signal (in terms of voltage and current) then there would be no color requirement. It also looks like R4 (Green) and R9 (Blue) are connected directly to where the LEDs would go, I can't tell for the Red LED maybe R14? But it also looks like it shares it common + with LED0, I wonder what color LED0 is, if red then quite possibly there is already a resistor in that circuit. Also the PCB appears to be silkscreened and drilled to directly accept a LED I'd imagine they'd have pads rather than through holes if you were meant to add your own LED circuitry (i.e. array and resistor) but they went to the extra expense to drill holes.

if you going by the diagram (they specify colours),
it was done by me (and the colours i chose are just to simplify the explanation) they've never put a diagram out there to follow.....

you can add whatever colour led you want (it doesnt matter)
(depending on the build that ive done, some times i've used green for the load/power)

also the board already has some led on it, i would have thought those resistors are for those led....
even if you add your own led,
the on-board led will also/still light up (so any resistors are meant for them)


like i said,
you may not need to add any resistors anyway,
the led are most probably powered by the battery (3.7V), so depending on the led you use you may not need to add anything.....
its up to you


i've just add the resistors to the led when wiring them up (look at the blue and the red led in the image)....
(i prefer to do it, as it also allows me to control the brightness)



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[jakejm79]

I was going by the specs listed of every seller of the Power Supply, if it didn't matter what color they would leave it up to the end user and not specify a specific color. For example a Blue LED tends a voltage drop of about 3.6V vs a Green of around 2.1V, when using a 5V supply (I'll make the assumption that is what is used since I don't think when trying to make the device as cheap as possible they would have tried to have multiple voltages available and we know the device outputs 5V), you are left with resistor requirements that differ quite a bit ~50 Ohms for Blue and ~100 Ohms for Green, i.e. putting a Green LED where they specify Blue would cause it to draw twice the current it should (leading to a shorter lifespan, but brighter output). If it didn't matter then:
A. They wouldn't specify a color for each position
B. They wouldn't already have LEDs on the board
C. I don't think the LEDs are powered directly from the battery, since that voltage can fluctuate quite a bit, also I haven't compared one directly to a PB1000C but with that the LEDs show activity even without a battery present.

Not trying to argue, just to figure out what is right.

[VeteranGamer]

I was going by the specs listed of every seller of the Power Supply, if it didn't matter what color they would leave it up to the end user and not specify a specific color. For example a Blue LED tends a voltage drop of about 3.6V vs a Green of around 2.1V, when using a 5V supply (I'll make the assumption that is what is used since I don't think when trying to make the device as cheap as possible they would have tried to have multiple voltages available and we know the device outputs 5V), you are left with resistor requirements that differ quite a bit ~50 Ohms for Blue and ~100 Ohms for Green, i.e. putting a Green LED where they specify Blue would cause it to draw twice the current it should (leading to a shorter lifespan, but brighter output). If it didn't matter then:
A. They wouldn't specify a color for each position
B. They wouldn't already have LEDs on the board
C. I don't think the LEDs are powered directly from the battery, since that voltage can fluctuate quite a bit, also I haven't compared one directly to a PB1000C but with that the LEDs show activity even without a battery present.

Not trying to argue, just to figure out what is right.

look i'm no expert....
(so if you have more knowledge in these matters, its not an argument)

i've made 7 Gameboy builds using this power supply,
so am just giving you feedback/advice on what i've done (and done without any issues)

i've always used resistors, its worked out well for me.....
(and i've always taken that the power supplied was 5v, and added resistors according to the led requirements)
(besides its not a big deal to add a resistor anyway, and they only cost pennies/cents)
(and are not a big issue to install/connect)

as i said its up to you.....



ps: any chance you can show the spec that are listed (it may help me in future builds)
(as the listings i've only ever come across, only tells you what the led on the board are for... no info for adding led)

thanks....

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[erik_gee]

From my own experience, I've measured the voltage at the charging and charged pins to be roughly 2v. I haven't checked the load pin voltage though.

Veteran, it seems like you use plain LEDs with colored plastic, rather than colored LEDs. Which is an advantage for you because you don't have to worry a out different collages for different pins, they will all glow the same. It's a good idea.

And Jake, it's interesting you say your green LEDs are rated at 2v, as green tends to be rated around 3-3.3v. Which is a problem since the pins are at 2v, they won't even turn on at a voltage difference.

That being said, again, the charging and charged pins have the same voltage, so any specification given that you have to use a certain led color is optional. Color does not matter, as long as it's rated to work 2-2.2v

[jakejm79]

There are often two types of Green, the is pure Green which does have the 3-3.3V rating, but then there is also the cheaper (and sometimes more common) Yellow/Green which have a rating of 2.1V which is about the same as Red, I think they are making the assumption you'd use the cheaper Yellow/Green LEDs.

I think Veteran's LEDs are in fact colored but they are also defused through colored plastic too. IME White LEDs defused through just a colored filter doesn't always work that well, compared to an actual colored LED.

[erik_gee]

There are often two types of Green, the is pure Green which does have the 3-3.3V rating, but then there is also the cheaper (and sometimes more common) Yellow/Green which have a rating of 2.1V which is about the same as Red, I think they are making the assumption you'd use the cheaper Yellow/Green LEDs.

I think Veteran's LEDs are in fact colored but they are also defused through colored plastic too. IME White LEDs defused through just a colored filter doesn't always work that well, compared to an actual colored LED.

Yes I have the yellow green and they are 2.1v, which are the ones I use. But the 3.3v green is the most common I've seen on the market place. And they are always labled yellow-green not just green .

Anyways, as I said, they are the same voltage on the pins so I doubt they have it set to any specific color, as veteran said. The description most likely said red,green, and blue because those are the colors they use on board for their smd LEDs. They probably just said the colors so you can distinguish them but I don't see any reason electrically why you could only use those colors as it is the same voltage.

[jakejm79]

That is a good point, I did just buy some tower LEDs like Veteran used and I was only able to find the Yellow/Green Green ones for cheap (i.e. same price as Red) all Pure Green ones were over 3x the price (comparable to White and Blue).