LEDs on a scaler

[Mutant_Xj]

I just got done building a switch to turn on LEDs. Now I'm one step closer to having working lights.

I followed how this guy built the switch How To Build A Servo LED Driver but I used a 1/4 watt 2.2 ohm resistor and a 1/2 watt 4.7 ohm resistor. Also I used a Hitec 645 board, positive to the LED is the pink wire that was going to the motor and negative is the brown, the black was heat shrinked and not used.

What resistors do I need to use? I hooked one LED up to the switch and it was nice and bright. I added a 1/4 watt 2.2 Ohm resistor and it was a lot dimmer. I tried a 1/2 watt 4.7 Ohm resistor and it was a little brighter but not much. I'm also powering the Rx with a CC BEC set to 6 volts.

I was planning to run one wire to the front of the body to power 4 LEDs (two white for headlight and two yellow for side marker lamps) ,one wire to the back to power two red leds, one wire to the roof to power 4 white LEDs, and one wire to the bumper to power two white LEDs. I got a piece of bread board from Radio Shack and circuit writer pen and was planning to have all the resistors on the board and have the board powered by the servo switch.

Also, When I hooked up the LEDs they strobe. I hooked up a white, red and yellow one at a time, the red was the least noticeable. Its super fast but its definitely not a solid stream of light. What would cause this, and what can I do to fix this? They also strobe when a resistor was hooked up as well.

I'm a total noob to electronics so if someone would help me out I'd be very grateful.

[wantAsummit]

Just a quick check: You said 2.2 and 4.7 ohms above. In the link you provided it is 2.2k and 4.7k. The "k" means 1000 so that would be 2,200 and 4,700 ohms.

[scrounge]

They make pre-wired plug-n-play light sets to do what you are wanting. Sounds easier than what your trying.

Check this-- www.hobbyLEDs.com

Hope this helps

[crawlhog]

you could get a switch from HEYOK who is a vendor on here and use your 3rd channel to turn the lights on and off. ive got 13 LED's on my truck, and i use my on / off 3rd channel switch to turn on the lights when i need them.

[Mutant_Xj]

They are 2.2K Ohm and 4.7K Ohm resistors I used, sorry.

scrounge - thanks for the link but those LEDs look like they're in a strip. I'm trying to make up scale headlights and tail lights to fit in my Cherokee build. Also buying something pre-made is too easy. I'm having more fun learning and challenging myself to getting these made up the way I want them not the way they cam in a kit.

[wantAsummit]

Try this link to figure out your current limiting resistors: LED Calculator - Current limiting resistor calculator for LED arrays

I am not sure about the strobe issue. Maybe once you have the correct resistors in there things will be better. This resistor is inline with the LED right? A smaller ohm value will result in a brighter LED.

[Mutant_Xj]

When I tried the two resistors it was in series with the LED. I even tried having the LED before the resistor and after the resistor. I'm wondering if it's the power source? I'm thinking about just having the signal wire go to the RX and powering the servo switch off of some AA nimh to see if that would change anything. I'm hoping that's not the case because I don't want to run extra batteries on the truck.

[wantAsummit]

Try something between 100 and 200 ohms to start with.

[Charlie-III]

Originally Posted by Mutant_Xj

They are 2.2K Ohm and 4.7K Ohm resistors I used, sorry.

scrounge - thanks for the link but those LEDs look like they're in a strip. I'm trying to make up scale headlights and tail lights to fit in my Cherokee build. Also buying something pre-made is too easy. I'm having more fun learning and challenging myself to getting these made up the way I want them not the way they came in a kit.

Dang, I had to do a double take to see it was a RC rig. Nice paint!!

I don't do LED's, thus I will let others discuss.

[Mutant_Xj]

wantAsummit - Thanks for the help, I'm going to go to the shack tomorrow and pick up a few more resistors.

Charlie-III - Thanks for the compliment!

[ridepate]

I just tape a 1.99 Lowes 10-LED flashlight to the roof...........













Just kidding....

[Mutant_Xj]

I got rid of the strobing, it was in the servo switch. I built a new servo switch out of a duatrax tactic servo. I used two 4.7K Ohm resistors to replace the pot instead of the 2.2k and 4.7k I used on the 645 board. I'm going to change the resistors on the 645 board and see if that was my problem.