How to wire LEDs

[Brake Weight]

I stripped the heat shrink from 1 of the 50 and it has a 470 resistor. Confirming a 3v LED. 2 AAs should push 6 or so LEDs.


This is why I want the power source to stay with the body. I also plan on some rain tray mounted lights on the sides.


So I did a little experiment last night through to this morning. I removed the resistor from 4 LEDs rated for 12v. I then soldered the wires back on and put on some heat shrink. I happened to have a battery holder for 2 AAs already, so I twisted the wires for the 4 LEDs, sans resistors, to the battery pack. I neglected to get an initial voltage because I didn't think of checking that until 1.5 hours later. The batteries used were fresh out of the package.

The drain looked like this:
1630-hooked up, no reading
1800-3.03v
2000-2.97v
2200-2.93v
Then this morning
0930-2.88v

So this is 17 hours of run time using 4 LEDs on a battery pack of 2 AA batteries. A 15.5 hour known drain of .15v isn't that much at all. I don't have some fancy big name multimeter like a Fluke or something, so the hundredths may be off some. But even if they are, the drain is infinitesimal.

[Brake Weight]

Originally Posted by Kel

Thumbs up for Heyok's lighting!

This.

I would have just further resistored the LEDs I have and then ended up with a bleeding system when it's ON. I do plan on putting a few more on that won't go with the body and I'll tying them in with the existing plug on my SCX10.

[wilbywise]

Thanks for the helpful info on this, I am hooked after my first try!

[heyok]

You're welcome!
Very nice work!

Al

[wilbywise]

Originally Posted by heyok

You're welcome!
Very nice work!

Al

Well I got my hands dirty and burned again this week.. I had been wanting to make a smaller LED light bar for awhile now and had the supplies to get started. It is rather bulky, I wish it could of been a bit smaller but it will work fine since It will be hidden into the roof rack. I wired everything together using the 150 ohm - 1/2 watt resistors and as soon as I finished I wondered if I could run a 9v to it. I checked out the LED calculator and it recommended the 330 ohm - 1/4 W for 9v. My main question is it safe to run the 9v? I tested it out and it ran fine but did feel slightly warm after 10 minutes run time. Here are a few pics to show my ghetto fabrications .. Thanks

[heyok]

It will work at 9 volts, but you will be wasting more energy in the form of heat. Just use a servo plug and get your power from the receiver.

[wilbywise]

Originally Posted by heyok

It will work at 9 volts, but you will be wasting more energy in the form of heat. Just use a servo plug and get your power from the receiver.

Thanks, I was just thinking overall that more volts = a brighter LED.. Not until I had everything all finished up did I realize I should have used different resistors. Thanks again for the input!

[Brake Weight]

What voltage is at the receiver?

[heyok]

Originally Posted by Brake Weight

What voltage is at the receiver?

Was that question meant for me?

Generally you find 6 volts at the receiver.

[Brake Weight]

It's for anyone really. I've been going most of the day and when I get a chance I'll check mine out to see. I didn't known of there was an industry standard for this.

[Brake Weight]

My Axial Honcho has this: Axial Led Control W/Led Lights (AXI24257) | RC Planet
At the servo connector it puts out 6v. At the end of the Axial LED Control, the headlights run about 15.8v and the tail lights are 6v. I checked the headlight voltage several times and it was the same 15.8v.

[heyok]

Originally Posted by Brake Weight

My Axial Honcho has this: Axial Led Control W/Led Lights (AXI24257) | RC Planet
At the servo connector it puts out 6v. At the end of the Axial LED Control, the headlights run about 15.8v and the tail lights are 6v. I checked the headlight voltage several times and it was the same 15.8v.

That circuit board has a special type of power supply called a DC to DC converter. It steps up the voltage. This lets them run a bunch of LEDs in series so they can get away with using one resistor per string of LEDs.

[Brake Weight]

The 2 red LED tail lights are the 6v plug-in series. The 2 white LED headlights are the 15.8v plug. When put into the 6v plug they are very dim. Also, there are no resistors between the plug and bulbs, so the white bulbs are running off of at least 7.9-8v each.

[Richterat83]

Question. Is it the same resistors to wire up 3mm led's?

[heyok]

Originally Posted by Richterat83

Question. Is it the same resistors to wire up 3mm led's?

Generally, yes. As long as the current and voltage specs are the same.

[BuddhaTat2]

Ok... Electricity and me are no buds.... That being said, I want to upgrade my 1/5 scale Jeep headlights to something brighter. I have the lighting system module already. But the single led is week sauce at best. I found these little dollar store flashlights take 3 aaa batteries, that fit in my headlight buckets. Now the question. Where do I solder my negative to the back of the leds, and do I need added resistors, or will the lighting system already limit the voltage for me?
Will it work? Hahahaha. I seriously am retarded when it comes to electronics.

[Brake Weight]

3-AAA batteries should be 4.5 volts. Depends on the current output of the existing harness. The wire up is simple. If it doesn't light up, swap wires.

[slimfire]

Originally Posted by heyok

That circuit board has a special type of power supply called a DC to DC converter. It steps up the voltage. This lets them run a bunch of LEDs in series so they can get away with using one resistor per string of LEDs.

Does it mean I can get rid of 2 of the 4 LEDs (connected in series) w/o worrying?
I mean there are 4 LEDs for the front, and I would like to use only 2 of them, can I simply cut the wire, remove the 2 unneeded LEDs and re solder the remaining LEDs I'm series?

Thanks for your kind reply!





- Slim -

[Brake Weight]

I'd suspect you'd need a resistor twice as big if using half the lights. If it's wired as heyok described.

[slimfire]

Originally Posted by Brake Weight

I'd suspect you'd need a resistor twice as big if using half the lights. If it's wired as heyok described.

If they are in series, should the board do the job of the resistor and as heyok wrote?

"That circuit board has a special type of power supply called a DC to DC converter. It steps up the voltage. This lets them run a bunch of LEDs in series so they can get away with using one resistor per string of LED"





- Slim -