High side switch for Car lights (50% Duty c.)

Hi, i'll try to be as short as possible and ON subject.

I've been trying for a while to turn my car lights ON/OFF with 50% duty cycle. My car's lights are turned on by a relay that is placed on HIGH SIDE and i don't want to change that !

What i tried: Circuit 1 (total fail, x2 mosfet fried) Mosfet: FDD4243 Transistor: 2n2222 AND 2n3904 |500x381

Circuit 2 (First time success, then i don't know what i did and fried the driver, THEN, instant fried another one)

Mosfet: IRF5305PBF Driver: TC4426EPA |500x300

My question is: What circuit should i try, what driver should i buy ? I found some High side p mosfet drivers on the internet but coudn't find them local

How much current do your lamps take?

Both these devices have Rds on of about 50mOhms, so with 10A flowing will dissipate 5W - without a heatsink they’ll fry!

Choose one with a much lower Rds on - <10mOhm.

And heatsink

Allan

What's the purpose of this? Reducing headlights effect?

What kind of headlights? Incan? HID? LED? 50% duty cycle implies you're turning them on and off. If even sensible, why? If your car's lighting system is HID with a ballast involved, then you're risking some serious voltages making you not be alive anymore.

You need to explain what your goal is, what you're working with, and why you want to do it. You should've done this BEFORE you went hooking things up without a clue.

Hi, You are using a PWM output of your controller and do you have the controller gnd connected to the 13V gnd?

Also you need to use a P-CH symbol in your diagrams. What model Arduino? And everything asked for in post #3.

Thanks.. Tom.. :)

allanhurst:
How much current do your lamps take?

Both these devices have Rds on of about 50mOhms, so with 10A flowing will dissipate 5W - without a heatsink they’ll fry!

Choose one with a much lower Rds on - <10mOhm.

And heatsink

Allan

With my second circuit i succeeded and either the driver or the mosfet wasn’t hot at all

The light bulbs consume about 2.6A at full brightness and i tried with 90/255

Johan_Ha:
What’s the purpose of this? Reducing headlights effect?

The reason for doing this is first because my car doesn’t have this function in ECU, to turn on the signal lights 50% like other cars specially all the cars in us. And second because i want to succeed

INTP:
What kind of headlights? Incan? HID? LED?
50% duty cycle implies you’re turning them on and off. If even sensible, why?
If your car’s lighting system is HID with a ballast involved, then you’re risking some serious voltages making you not be alive anymore.

You need to explain what your goal is, what you’re working with, and why you want to do it. You should’ve done this BEFORE you went hooking things up without a clue.

My car uses halogen ones and the voltage is still 12-14v
I’ve done this externally with a low load and everything worked but after doing it on my car and exploited it hard with fade effects and beating effects the arduino got a brainfreeze and the driver silently died and then getting hot(second circuit)

TomGeorge:
Hi,
You are using a PWM output of your controller and do you have the controller gnd connected to the 13V gnd?

Also you need to use a P-CH symbol in your diagrams.
What model Arduino?
And everything asked for in post #3.

Thanks… Tom… :slight_smile:

Yes, i connected all the grounds of all the circuits and i read somewhere that this might be a problem because the driver doesn’t accept more then negative 5v

Sorry for the diagram, i didn’t realised it when i did it.
Arduino MEGA

The right symbol is very important. I always use the MOSFET symbols which show the body diode. I always get it backwards if I don't.

How about forgetting the Arduino and all the toastable stuff and connect the headlights in series. That would drop the voltage to 6.5 V per bulb.

Johan_Ha: How about forgetting the Arduino and all the toastable stuff and connect the headlights in series. That would drop the voltage to 6.5 V per bulb.

I can also use a regulator to so this and also a switch

But the idea is that i want to build this high side switch controlled by arduino for more reasons that are off topic

Hi,

The reason for doing this is first because my car doesn't have this function in ECU, to turn on the signal lights 50% like other cars specially all the cars in us. And second because i want to succeed

Ahhh.. its because in the US you have red tail lights with one lamp/LED and it runs 50% brightness for running/parking and flashes up to 100% when the brake is applied. Is that what you are trying to accomplish, there is another thread on the forum trying to do that too with a custom rear light array, turn indicators, brake ,reverse the lot.

[soapbox} Stupid idea, lamp fails, no tail lamp, no brake. Two lamps one park, one brake if one fails you still have the other function, unfortunately the automotive technology is moving to one light source instead of two. [/soapbox]

Tom... :)

TomGeorge:
Hi,Ahhh… its because in the US you have red tail lights with one lamp/LED and it runs 50% brightness for running/parking and flashes up to 100% when the brake is applied.
Is that what you are trying to accomplish, there is another thread on the forum trying to do that too with a custom rear light array, turn indicators, brake ,reverse the lot.

[soapbox}
Stupid idea, lamp fails, no tail lamp, no brake.
Two lamps one park, one brake if one fails you still have the other function, unfortunately the automotive technology is moving to one light source instead of two.
[/soapbox]

Tom… :slight_smile:

It’s about the signal lights

Only the front ones!

The whole circuit for switching between the normal signal lights and dimmed singal lights works perfectly

Only the dimming part doesn’t, there is the circuit but using the old build for driving the mosfet witch failed as i said in the first post

I need help with the build of the high side switch

Hi,
Please post a picture of your project so we can see your component layout.

The high side driver TC4426EPA you said did work, why not try it again, this time don’t do something “stupid” including change connections with power truned on.

Please put a fuse in the power line to the battery.

Tom… :slight_smile:

TomGeorge: Hi, Please post a picture of your project so we can see your component layout.

The high side driver TC4426EPA you said did work, why not try it again, this time don't do something "stupid" including change connections with power truned on.

Please put a fuse in the power line to the battery.

Tom... :)

I had a fuse. Now i have no more driver to test it, new ones come tuesday but now i read about them and it seems like they are made to drive low side switch

Also i saw a driver which drive High side using a n channel mosfet, and i think i'll try this too

Anyway.. I don't know what should i do right now and this is why i posted this

Edit: also i didn't change the connections What fried my driver was a bug in fading the bulbs off while doing something else, that freezed the arduino for a second( freezed not by delay function), a code bug that i didn't tought it can affect or even fry the driver

Edit2:tnx for replys, i'll post a photo of the actual circuit tomorrow, keep an eye on this :d

prologikus:
My car uses halogen…

AFAIK dimming halogen lights reduces bulb life.

http://www.topbulb.com/blog/dimming-alters-halogen-cycle/

Leo…

Wawa: AFAIK dimming halogen lights reduces bulb life.

http://www.topbulb.com/blog/dimming-alters-halogen-cycle/

Leo..

And automotive bulbs (and 3-way indoor bulbs for that matter) achieve their different brightness levels by actually having 2 separate filaments. This PWM idea is bass ackwards. PWM is chosen for LEDs because LEDs don't behave like incans. And dimming incans just creates more heat as they are designed for a particular temp.

Here is the bulb |375x500

And the circuit |500x374 |500x375

Any ideas why this wasn't working and how to build a new better one?

Switch to an LED bulb of the same shape and your project is vastly simplified.

INTP: Switch to an LED bulb of the same shape and your project is vastly simplified.

I realise that my bulb might be an incandescent one so it won't hurt as much as it was an halogen one.

I don't want to change my car lights, too expensive, less or more brightness and also not the OEM color of the lights

Either way i still need to build a high side switch because the lights are permanently connected to ground and switched from a relay on high side.

Edit: https://youtu.be/y4i4YaTX3hs I saw this video and i'm thinking of replicating it, since i got no other suggestions from here

They have amber LEDs made for automotive bulb replacements, and they are cheaper than all the money you've spent so far killing things. But you've always been the type to just make stuff up, so good luck.