LED Puzzle answer

SAI_Peregrinus on July 5, 2018 [?]

The bit inside the 9 volt connector isn't really logic. The flip-flops and Schmitt trigger gates are just to generate square waves at 3 different frequencies. There's also a small power supply to drop the 9V down to 6.2V for the input of that, some comparators, and a bit of filtering. The LEDs contain LC filters, tuned such that they'll light (visibly) when the appropriate frequency is applied. Touching the wire in different places creates a different parasitic load, which is detected by one of the comparators. That comparator then toggles the clock generator for the appropriate frequency, turning that LED off or on.

As with all of his circuits it's a brilliantly simple idea implemented in a ridiculously constrained space.

Reply to
ABLE1
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Where do you get LEDs that incorporate LC filters???

I'd think it more likely the LEDs are controlled by PWM comms like some of the tri-color LEDs. But I've never seen any that were controlled over the power wire and looked like the standard T1-3/4 devices.

Does anyone know what exactly is specified when using the term T1-3/4? It is used with 5 mm LEDs but also a couple of different light bulb shapes, "w edge" and "flange" for two. Is T1-3/4 just the diameter of the bulb like 5 mm?

The Youtube page says to check his Google account for the solution but even that is too complex for me. What account is he talking about? Is it one of those features that Google obsoleted a while back?

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  Rick C. 

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Reply to
Ricketty C

of the tri-color LEDs. But I've never seen any that were controlled over t he power wire and looked like the standard T1-3/4 devices.

t is used with 5 mm LEDs but also a couple of different light bulb shapes, "wedge" and "flange" for two. Is T1-3/4 just the diameter of the bulb like 5 mm?

en that is too complex for me. What account is he talking about? Is it on e of those features that Google obsoleted a while back?

yep google+ doesn't exist anymore

I'd guess he has modified the LEDs like these for another puzzle

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Reply to
Lasse Langwadt Christensen

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9V

d
d

e of the tri-color LEDs. But I've never seen any that were controlled over the power wire and looked like the standard T1-3/4 devices.

It is used with 5 mm LEDs but also a couple of different light bulb shapes , "wedge" and "flange" for two. Is T1-3/4 just the diameter of the bulb li ke 5 mm?

even that is too complex for me. What account is he talking about? Is it one of those features that Google obsoleted a while back?

Wow! That's some pretty cool handiwork. I don't have a chance of doing th at. Essential tremor took away my ability to do fine work some 20 years ag o. I built a small power supply module using 0603 components and some of t hose parts had to be resoldered probably 20 times. Then I "discovered" con tract manufacturing.

The eyes are shot too, but they have some pretty cool aids for the aged the se days.

--
  Rick C. 

  + Get 1,000 miles of free Supercharging 
 Click to see the full signature
Reply to
Ricketty C

s
9V

d
d

e of the tri-color LEDs. But I've never seen any that were controlled over the power wire and looked like the standard T1-3/4 devices.

It is used with 5 mm LEDs but also a couple of different light bulb shapes , "wedge" and "flange" for two. Is T1-3/4 just the diameter of the bulb li ke 5 mm?

even that is too complex for me. What account is he talking about? Is it one of those features that Google obsoleted a while back?

His power supply is brutal --

74LV74:
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through 22 ohms to 9V... schematic:

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Cheers, James Arthur

Reply to
dagmargoodboat

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