Led taillight schematic i have designed is it gonna work?

Thread Starter

jeffordsra

Joined May 5, 2021
4
the way my circuit works we have 4 wires that will be connected constant 12v , gnd ,brake signal , dim signal when dim is applied all led light up but dim, when brake is applied each array lights up one after the other and then stays on until the signal is turned off. is this correct
 

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djsfantasi

Joined Apr 11, 2010
7,693
Your parts identifications are too small, so I can’t see what you’re using.

The part labeled CD4017 doesn’t look like the correct pinout. It only has 14 pins; the CD4017 has 16.

What are you trying to do with the brake and running light signals? They don’t control the LEDs. The LEDs state connects both signal nodes to ground, if the transistors are NPN transistors.

Or not quite... In each column, if the LEDs are off, current will flow through the diode and connect the two signals to ground. If the LEDs are on, the signal nodes will not be connected to ground. Is this what you want?
 

Thread Starter

jeffordsra

Joined May 5, 2021
4
i enlarged the schematic the brake and running light signals are just 12 volts coming from the car wiring harness i was trying to use the transistors as a relay . so essentially what i am trying to do is give the board a constant 12v and gnd then when i turn on the running lights i want all 42 led to come on but at half brightness and when the brakes are pressed i would like for the led to come on sequentially at full brightness and then stay on until the brake pedal is releasedschematic.png
 

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Thread Starter

jeffordsra

Joined May 5, 2021
4
Or not quite... In each column, if the LEDs are off, current will flow through the diode and connect the two signals to ground. If the LEDs are on, the signal nodes will not be connected to ground. Is this what you want?
i think i need it to be the opposite when the led are on it need to go to ground
 

AnalogKid

Joined Aug 1, 2013
9,257
1. How are you going to run 6 LEDs in series on only 12 V? That leaves very little headroom, if any, for a current limiting impedance.

2. I don't see anything that will affect LED brightness. Please explain how you think your circuit works. Also, please add labels to the wires that cause all LEDs to be on, the dimming command, etc.

3. As above, all of the LEDs have a current path to GND through the Q5 and Q6 transistor base-emitter junctions and their base resistors. Since only one of <Q1 - Q3> can be on at any time, the other strings will assure that Q5 and Q6 are on constantly.

4. You can have sequential lights as turn signals. You can not have them as brake lights.

5. If your dimming plan is that, for example, Q1 shorts out D1 to increase the voltage for the first two LED strings by 0.6 V (and thus increase the LED current), I think the change in brightness will be much less than 50%.

ak
 
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Audioguru again

Joined Oct 21, 2019
3,199
Many people post schematics with parts so far apart that the schematic is as large as my neighborhood and the text is tiny and cannot be seen. I could not enlarge the schematic clearly but I cropped it then it could be clearly enlarged.

In many countries it is illegal to tamper with vehicle lighting and signalling.
 

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Thread Starter

jeffordsra

Joined May 5, 2021
4
thanks for the help i think i am going to step back to the basics and try again i dont understand enough about the circuit to explain it i have been using example circuits but i guess i dont understand them either lol but thanks everyone for your time
 

BobaMosfet

Joined Jul 1, 2009
1,776
the way my circuit works we have 4 wires that will be connected constant 12v , gnd ,brake signal , dim signal when dim is applied all led light up but dim, when brake is applied each array lights up one after the other and then stays on until the signal is turned off. is this correct
This is a good opportunity to breadboard it and test it...

If you're new to electronics- get help. Read this:

Title: Understanding Basic Electronics, 1st Ed.
Publisher: The American Radio Relay League
ISBN: 0-87259-398-3

Or go here:

1620325332436.png
 
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