Adding LEDs to already existing LEDs on PCB?

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Sir SouthSeaPirate. . . . . . . .aka . . . . . AAAAAAAAAAAARRRGH MATEY !

Since I am seeing only 7 internal LED's, that would just be a match for this one chip interfacing circuit, that is just stuffed with transistors.
It would totally snooze on the meager drive currents to each cloned 20ma Hi Intensity LED . . .mounted offboard . . . . .being wire connected .


Units Relevant Schematic:


IC's datasheet :

http://pdf.datasheetcatalog.com/datasheet2/f/0c6x6a46ig46qlxf3j2qsaii8o3y.pdf


73s de Edd

 

Sir SouthSeaPirate. . . . . . . .

Not even scratching the surface of my head . . . . .

So you think I could just wire in 20ma LEDs on each and be fine?

NOPE . . . .LED's don't readily share . . . . unless you are OK with . . .vewy-vewy dim..
You need to use that isolative manner prescribed . . . the original LED's won't EVEN slightly detect the additional remoted LEDs presence and that added set will operate like gangbusters.

You need to give the supply voltage coming in from the wall wart connector at the top left corner.

I can see the 1 .8 V and 3.3 supply lines but wonder about the highest DC voltage level present.

Need a memory refresh . . . . I know about the typical / activity flashing functions, but what are the ratio of lit LEDS to unlit ones ?

73s de Edd

 

Sir SouthSeaPirate . . . . . . . .

On the schematic, does 'TO LEDS' refer to patching to the LEDs on the board?

At each of the on board LEDs, they have their current limiting, surface mount resistor being just to their side.
At that junction is where you would want to solder tack in a small gauge wire *** that goes BACK to an associated 47k base resistor.

If so, what side of the on board LEDs to solder to? Assuming it matters.

You are soldering to the top, component side of the board

'LED 1' and so forth refer to my remote LED's yes?

Yeth

What resistors do I need? I see 1/2watt, 1/4watt, etc.

The left set could use 1/4 watt, the right set would loaf with 1/2 watt units

My personal construction technique would be to use some fine gauge insulated "wire wrap" wire and connect one to each junction and thread bind them and route the amassed cable bunch back to the left side of the board where the IC would be mounted.
Each wire is then going to its associative 47K res at the IC.

*** If you have none, the best available source after that would be some of the 26 ga insulated copper wire stripped from a CAT 5 cable.

Also if you have ZERO pcb fabrication experience, since this is being a linear . . . in one side . . . out the other side, it might incorporate "dead bug" mount configuration of the IC.

In that situation, the IC is mounted legs up, on a small insulative board with a drop of super glue, and the leads splayed out, such that wire connections can then be made to them . . . . . such as is being seen at the two left leads in the foreground below.

ILLUSTRATION:



Then, you build up the mounting and wiring of the wire remoted LED's, as you wound have them.

STILL need the DC voltage level coming from the DC power wall wart connector, as seen at the units left rear.

73s de Edd


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