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Newbie request - Stacking light kit/project

Charley88

New Member
Hi all, I am new here, just registered to see if any of ya'll can help. I am trying to find a project/kit to control lights I wish to put in my car.

Here is the idea. I wish to fit 5 x COB 150mm long LED strips in red, which are to be brake lights. I want press the brake pedal, and the middle/central 1 will light up and stay on, followed by the ones either side of the middle one to light and stay on, then the outer most 2 to light and stay on, so all 5 lights will stay on whilst the brake pedal is depressed, then all go off when the brake pedal is released. So the sequence will be 3, + 2+4, + 1+5, all on, all off.

Has anyone already done this or is it something new? I've tried looking online but as yet haven't found any builds to match.
 

audioguru

Well-Known Member
Most Helpful Member
In a few modern countries, it is illegal to tamper with the lighting on a road vehicle because the new lights might be too dim, too bright or not have a wide enough viewing angle. Your idea to begin with some lights then add more lights would not be acceptable.
 

dougy83

Well-Known Member
You can use two timers to turn on the "2+4" and "1+5" LEDs after a delay. The "3" LED is always connected across the power supply. The power supply is taken from the existing brake light.

For the timers, you can use half a 4093 (schmitt-trigger NAND), or similar, or two 555 timers. I've attached a schematic for the 4093 version. As shown, I think the delay will be something like 0.7 seconds, and 1.44 seconds for the respective LEDs.
 

Attachments

Charley88

New Member
Audioguru, it's fine, I can always add an inline toggle switch and just switch it off if the cops stop me.

Dougy, thats great, thanks. Can I ask, what are the bullet shaped things in the diagram? Also, the 100k and 220k resistors are the time control/delay rights, so I can try bigger resistances or even variable resistors in their place?
 

audioguru

Well-Known Member
Most Helpful Member
Audioguru, it's fine, I can always add an inline toggle switch and just switch it off if the cops stop me.
Why did they make that law about tampering with lighting? To reduce crashes of course. Please do not drive on my roads.
 

Charley88

New Member
So I have been searching online for the 4093 ic diagram, and quite a few internal circuits come up, so I am confused even more now.
I found this website/page, and it shows multiple internal circuits, can dougy tell me which version of the chip I should get please? Or would it be easier to get a couple of 555's?

 

audioguru

Well-Known Member
Most Helpful Member
Since you do not know about simple common electronic circuits like a CD4093B then your illegal brake light circuit will certainly cause a bad accident.
 

dougy83

Well-Known Member
I got this image online of the 4093, which terminals do I connect to what please?
Sure:
118543
I added a resistor, zener diode and capacitor (on the left) to hopefully get rid of voltage spikes from the alternator. The transistors that are driving the LEDs (terminals marked with "G"/"D"/"S" - i.e. gate/drain/source) are N-channel mosfets; choose some with voltage rating above 20V, and current rating above whatever the LED strips use.

So I have been searching online for the 4093 ic diagram, and quite a few internal circuits come up, so I am confused even more now.
The 4093 only has one pinout that I know of, which is the one you posted first.

Or would it be easier to get a couple of 555's?
It's just as simple using two 555s. I can draw the schematic if you want.
 

Charley88

New Member
Sure:
View attachment 118543
I added a resistor, zener diode and capacitor (on the left) to hopefully get rid of voltage spikes from the alternator. The transistors that are driving the LEDs (terminals marked with "G"/"D"/"S" - i.e. gate/drain/source) are N-channel mosfets; choose some with voltage rating above 20V, and current rating above whatever the LED strips use.

The 4093 only has one pinout that I know of, which is the one you posted first.

It's just as simple using two 555s. I can draw the schematic if you want.

Hi Dougy, thanks alot for that, that makes alot more sense now. Sometimes more detail is easier to understand. Yes, could you do a schematic using a couple of 555's aswell please, I have 2 sitting around I can use anyway. Thanks again.
 

dougy83

Well-Known Member
If you already have the 555s there, then all the better. Here's the franken-schem:
118547
And regarding your question about using a variable resistor in place of the resistor, yes, you can. The delay is proportional to the value of the resistor.

EDIT: the 100 ohm resistor on the left should be reduced to possibly 10 ohms, because the 555 timers use more current than the 4093.
 

kubeek

Well-Known Member
Most Helpful Member
Why did they make that law about tampering with lighting? To reduce crashes of course. Please do not drive on my roads.
Exactly, a few days ago I almost crashed into some moron with aftermarket rear lights, beacuse in the bright sunlight shining directly at the rear lights the turn signal just couldn´ t be seen. I noticed it faintly blinking when I was about two meters behind him and had to brake hard to avoid a crash.
 

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