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Superluminal

Led wiring help with TLU-01

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Hello, im am having an issue with some led head and tail lights wiring on a TLU-01 light controller.

I have wired up pairs of 3.5 and 5mm red and warm white in the following congiguration;

Head lights each side;

2no 5mm warm white led to one jst plug.

2no 3mm warm white led to one jst plug.

Rear lights each side;

2no 5mm red led to one jst plug.

2no 3mm red led to one jst plug.

However only the 5mm red ones light up. The 3mm reds and none of the white leds work. I have tried different combinations of the ports on the tlu-01 but still only the 5mm reds come on.

Any help really appreciateed.

Resized_20190409_213157_6087.jpeg

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Just tried some other white leds that have the blue tint - these seem to work. Do warm white leds work differently to the cold white ones?

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Maybe a silly question,  but did you make sure you had the polarity of the LED leads in the correct orientation?

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15 minutes ago, Superluminal said:

Just tried some other white leds that have the blue tint - these seem to work. Do warm white leds work differently to the cold white ones?

Only slightly different current draw, but the TLU compensates for whatever values you have (which is why I like the unit more so than the generic Chinese versions that call for inline resistors) FWIW, I've used warm whites on my own TLU1 setups,  and had no problems whatsoever.

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Yes- all red to black. Seems strange how not a single one of the warm whites doesnt light up. I know my soldering is shonky at best but would have thought one in four might be ok bearing in mind the pair of 5mm reds works fine.

They were all all pre wiref leds i bought off ebay (uk seller) that I soldered on the jst connectors to. I dont know how to test leds without using the light controller - is there a chance they are all faulty leds? Maybe I should strip them down and resolder again.

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3 minutes ago, Superluminal said:

Yes- all red to black. Seems strange how not a single one of the warm whites doesnt light up. I know my soldering is shonky at best but would have thought one in four might be ok bearing in mind the pair of 5mm reds works fine.

No, I meant short and long leads on the LEDs. They're diodes, so they are polar unlike incandescent bulbs.

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4 minutes ago, Superluminal said:

They are pre-wired with a black and red lead the same length?

Okay, gotcha. That'll eliminates that.

How about supply voltage? I think the TLU01 requireS 7.2V?

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Im not sure - i bought them a few months ago. Will see if they are in my ebay purchase history still.

Ok just checked - I bought them all at the same time from the same seller. Listing says they are all 9v - 12v. This is bad right?

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Okay, after a ridiculous amount of searching,  I cannot find the thread that mentions that a 6V SUPPLY voltage is sufficient to drive the TLU01 unit, but you're likely to be fine on the supply side.

The LEDs shouldn't have inline resistors, or they will work very much like you're describing. If the ones you bought are 9 or 12v, I can guarantee they do have inline resistors. Most unregulated LEDs can't handle that much voltage/ current. The TLU01 is unique in that it regulates the current so there's no need for a bunch of different resistors.

Check your values and you'll probably have your answer 👍

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Im running the tlu-01 straight of the 7.2v nimh battery connector before it goes to the ESC as shown in the instructions. So i assume its getting full 7.2 as its not running off the ESC Bec reduction.

No resistors on the leds I can see or feel under the heat shrink.  Im assuming now I need to buy led's that will operate at less then the 9v listed for the ones i got?

Thanks for helping though, really appreciated.

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17 minutes ago, Superluminal said:

Im not sure - i bought them a few months ago. Will see if they are in my ebay purchase history still.

Ok just checked - I bought them all at the same time from the same seller. Listing says they are all 9v - 12v. This is bad right?

Yeah, that's a no-go with the TLU01. 😕 You need LEDs that are specifically without resistors. The way you have them wired is correct, but the resistance is causing your symptoms.

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4 minutes ago, Superluminal said:

Im running the tlu-01 straight of the 7.2v nimh battery connector before it goes to the ESC as shown in the instructions. So i assume its getting full 7.2 as its not running off the ESC Bec reduction.

No resistors on the leds I can see or feel under the heat shrink. 

If they're 9 and 12v, they should have some means of current reduction. Might be integrated resistors.

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Do you have a 3V lithium button cell handy? This is a good way to test if your LEDs will work with lower voltage.

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Thats thst solved then. Thank youbfor the help. Will strip them down and cut the resistors off and try again.

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9 minutes ago, Superluminal said:

Thats thst solved then. Thank youbfor the help. Will strip them down and cut the resistors off and try again.

Yep, was just going to suggest that. All LEDs are similar in that they can't run on unregulated current.  Anymore than 20 milliamps and your diode is toast. Some bulb colors can tolerate more or less draw, which is why some of yours worked and some didn't.

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Thank you again for ghe help  - I would never have worked that out otherwise. I cant stand electrics - even when explained in as simple terms as possible I still cant grasps the basics. Maybe if electric was visible and didnt move so quickly and I could see where it was going and what it was doing I would "get" it.

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10 minutes ago, Superluminal said:

Thank you again for ghe help  - I would never have worked that out otherwise. I cant stand electrics - even when explained in as simple terms as possible I still cant grasps the basics. Maybe if electric was visible and didnt move so quickly and I could see where it was going and what it was doing I would "get" it.

These were my exact thoughts too before I read this book:

https://books.google.com/books/about/There_are_No_Electrons.html?id=8e01Q3QSrS4C

It's an embarrassingly nerdy book, but it really helped me to visualize the physics behind the scary invisible force that has a reputation for biting you when provoked 😄 We as humans tend to distrust things we don't understand ¯\_(ツ)_/¯

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Well have spent tonight cutting the resistors off, resoldering and re-heat shrinking. And none of the white leds and 3mm reds still dont work. So exactly the same as before.

If I buy completely new led's is there something specific in the description I should look for that means they will work with the tamiya light controller? Ie should I look for ones that say a certain voltage? There must be some that will work as the 5mm reds seem to. I can just about solder the mini jst connectors on to the ends of them but all the rest I cant understand.

 

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LED1.png.f97c3c7f5d84db0c0075f5146c1fb088.png

Here is how you can check plus and minus when the legs got cut.

The TLU can handle 2-3 white LED in series and 2-4 orange/red on one port. (Depends a bit on led and battery, just try)

The size of the led 3or5 mm doesn't matter it's the color that determines the voltage.

Fun read

You can kill a led if you heat them to much while soldering.

If  led doesn't light up try swap the ± on the TLU port, providing the led in series are all connected correctly.

 

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4 hours ago, Superluminal said:

You bought 9V-12v again? Those aren't going to work for you -- you need something that operates on 5V~6V. Pretty much any pre-wired LED that's made for automotive applications is going to have too high of resistance to work correctly with the TLU. I'm not sure where you are looking but I thought eBay might have the lower voltage WITHOUT resistors.

Also, I agree with @waterbok in regards to overheating the LED leads -- it doesn't take more than a split second too long and you've fried the bulb's internals. Soldering these kind of junctions requires a little practice, so the pre-wired items would probably be the better choice for you.

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No I havent bought them again, those were the ones I bought originally and have now cut the resistor off (edited my post to clarify :lol:) I have wired the polarity correctly. The resistor wss soldered to the positive. I cut the resistor off them and just extended the positive wire back up to the leg on the led. I didnt touch the negative leg/wire.

Maybe I fried them all? There wasnt a very long leg left after cutting the resistor off.

https://www.ebay.co.uk/itm/5V-to-6V-Pre-Wired-High-Brightness-3mm-Clear-LED-Various-Colours-Constant/123035920319?var=423469341736&hash=item1ca58327bf:g:VBkAAOSwXkJatMOn

These seem to be the only warm white pre-wired leds at 5v to 6v from the uk. The description says that 7v will will fry them. Does the TLU-01 light unit reduce the voltage or output 7.2v straight from the battery? 

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