US style - car lights (signal lights)

Hi, in my country there’s a module called us style lights for cars, it cost about 10 usd but it’s more nice if i can build it myself using arduino, so i designed a circuit that may work using a mosfet, a voltage divider with a zener diode to protect my arduino input pin used to send PWM signal to that mos

Here is a example of a car using this module

The module is originaly set to 50% duty and is connected like so :
there are 3 wires from the module
1 is connected to the positive wire from the general lights
2 is connected to one side of the signal wire (CUTTED)
3 is connected to the other side of the cutted wire of the signal lights (from the car)

Here is the design i tought about

link: http://i.giphy.com/3o7TKuZGIx4Z7l9iOQ.gif

I’ll use CEP50N06 as mosfet

with RDS(ON) = 22mΩ (typ)
I x I x R = P.
2.8A both signal lights 100%
so
2.8 x 2.8 x .022 = 0.18P (W)
so with R-theta junction-ambient of 62.5 C/W it gives me 11.25C right ? not much considering i’ll use a sink too

EDIT: For the Voltage divider i’ll use 30k:13k resistors
good ?

What i’m not sure is:
1.Can the Mosfet handle it + should i use a resistor too ?

2.Can the voltage divider + zener real protect my arduino input pin and also read the voltage
(in the circuit i used a 100M resistor to simulate the arduino input pin, but i’ll actualy use a i/o expander to read it, i’ll read later the resistence of it MCP23017)

3.Why there is still some voltage where i marked ghost voltage in the circuit, when i already used a diode (fwv voltage /1a - 805m, from the app settings), in reallity i’ll use what i have (in4001)

4.That “ghost voltage” can actualy harm something if there is no way of getting it down ?

5.Fuses ?
Ignore any coding, i’ll be a simple if statement with some variables

Circuit text (in case)

 0.000005 10.20027730826997 65 5 43
v 720 656 848 656 0 0 40 16 0 0 0.5
162 848 272 720 272 1 2.1024259 1 0 0
162 976 176 848 176 1 2.1024259 1 0 0
x 871 211 927 214 0 24 lights
x 743 312 805 315 0 24 signal
x 861 600 990 603 0 24 lights switch
x 707 630 838 633 0 15 voltage for car lights
x 1106 339 1275 342 0 14 car's right/left signal switch
w 976 544 848 544 0
v 1088 416 1088 336 0 0 40 15 0 0 0.5
x 1097 478 1194 481 0 15 Ground comun
x 1113 379 1223 382 0 15 voltage for signal
w 848 272 848 336 0
g 848 176 848 208 0
g 720 272 720 304 0
g 1088 416 1088 448 0
g 720 656 720 688 0
f 912 400 912 336 0 1.5 0.02
w 848 336 896 336 0
w 976 544 976 288 0
w 976 176 976 288 0
d 976 288 928 288 1 0.805904783
w 928 288 928 336 0
d 992 336 896 336 1 1
x 927 385 956 388 0 15 50%
s 1088 336 1088 272 0 1 false
w 1056 272 1088 272 0
x 1043 228 1103 231 0 18 <relay>
r 848 544 768 544 0 27000
r 768 544 704 544 0 10000
g 704 544 704 576 0
w 768 480 816 480 2
g 1024 672 1008 672 0
w 768 544 768 480 1
s 768 480 720 480 0 0 false
z 656 480 720 480 1 0.805904783 5.1
g 656 480 656 512 0
r 816 480 896 480 0 100000000
w 896 480 944 480 1
g 944 480 944 512 0
R 912 400 912 432 0 2 24999.999999999996 5 0 0 0.5
x 965 498 1060 501 0 13 arduino input pin
x 675 458 729 461 0 13 5.1 zener
x 751 571 789 574 0 13 divider
x 813 502 916 505 0 13 rezistenta arduino
w 1056 272 1056 336 0
w 1056 336 992 336 2
x 1010 257 1147 260 0 24 <not shown>
x 660 383 901 386 0 15 just duty cyrcle controled by input pin
x 790 405 901 408 0 15 arduino PWM pin
x 981 348 1068 351 0 15 ghost voltage
s 848 544 848 656 0 0 false

Please define “us style lights for cars”. All I see is a car with indicators lit. How is it different from “normal” lights?

Weedpharma

weedpharma: Please define "us style lights for cars". All I see is a car with indicators lit. How is it different from "normal" lights?

Weedpharma

The signal lights are on at about 50% of their power, in normal, the signal lights are only used for signals (right/left)

1.Can the Mosfet handle it + should i use a resistor too ?

What is "it" that you wonder if the MOSFET can handle?

2.Can the voltage divider + zener real protect my arduino input pin and also read the voltage

If the values of the resistors in the voltage divider are correct, yes. I can't tell, because I can't stand that flashy GIF.

3.Why there is still some voltage where i marked ghost voltage in the circuit, when i already used a diode

How are you measuring that voltage? If that is at an Arduino pin, you are not pulling the pin LOW when the car input is missing (the turn signal is off).

4.That "ghost voltage" can actualy harm something if there is no way of getting it down ?

It could, but the supposition is incorrect. It can be 0.

5.Fuses ?

We don't need no steeeenking fuses. Smoke is a good thing.

PaulS: What is "it" that you wonder if the MOSFET can handle?

Powering up the signal lights without crashing/blowing, i also did some math with what i got from the internet but i don't know if that is correct ... + a 30k resistor on the gate can be a problem ? i once read that it protect the arduino pin from shorting

PaulS: If the values of the resistors in the voltage divider are correct, yes. I can't tell, because I can't stand that flashy GIF.

So, no image for you ? i can convert it to jpg if you want. Also, the voltage divider values are 30k:13k(they are also in the first post) (The voltage from the car is 11-16V)

PaulS: How are you measuring that voltage? If that is at an Arduino pin, you are not pulling the pin LOW when the car input is missing (the turn signal is off).

i didn't measured any voltage, it's just the program that tell me that the voltage/current go thought the diode back to the ECU of the car or whatever controls it (witch is not good at all)

PaulS: We don't need no steeeenking fuses. Smoke is a good thing.

i don't understand, but anyway i'll use a 3A fuse just in case ..

These days i want to build it in real life and see how it works, can you tell me if there is a problem with my circuit, and how to fix it ? i'm a beginner and i'm afraid i'll blow something ..