Ugh... Just closed the tab and lost my draft

Ok from scratch.

Hi, my name is Jon and this is my first post.

The Project:
Motorcycle Gauge (Arduino, Stepper, OLED display, LED backlight, LED indicator lights)

I have been wanting to build this for some time and I have the necessary skills and resources, but I keep getting overwhelmed when is comes to driving the LEDs for the backlight (and packaging the OLEDs, but that is outside this scope).

I have a basic understanding of how all these parts work, and have looked at many different solutions, but I am unsure as to which are the simplest/most reliable/or best (if there is such a thing).

Specifications:
Supply Voltage= 11 -1 4VDC
Temp= -5 - 40C
Speed= -1 - 60m/s
Vibration = Y

LEDs:
~30 @ 3.45V 20mA + (~12 @ 3.45V 20mA or ~12 @ 3.45V 20mA) + (6 @ 2.5-4v 20mA individually switched)

The 30 White and 12 White sets need to be dimmable (switch or LDR), others probably not.

I have looked at:
Purpose built LED drivers (NSI45020 etc.)
Boost Circuits/Drivers (MC34063A, LT3465 etc.)
Linear Regulators (LM317etc.)

I need to figure out what will work well for me in this application. Maybe I should just ignore these fancy chips and use BJTs? I don't know.
It seems likely that the (30) and (2x12) sets of LEDs will each need one current limiting chip, while the 6 independent LEDs could use another, or individual NSI45020.

Anyways, I need some guidance here so I can make some good choices/learn about something new and eventually get this project off the ground.

LED Schematic for reference (quantities subject to change, just for visual on arrangement)


BTW: I have Multisim, Diptrace, and Solidworks. The latter two I am using. I will start using Multisim when I have a better plan of what I'm doing.

 

Ugh... Just closed the tab and lost my draft

Occasionally, reopening the page will recover at least a portion of what was written. It's not a reliable solution and probably depends on your browser and OS, but it has saved me a few times. It's awfully
annoying when it fails. For long posts (and your's is close to qualifying), I sometimes use a text editor or save a draft in my e-mail.

 

Thanks wayneh, I tried Ctrl+shift+T but Chrome let me down. I had it open for over a day so it is definitely my fault.

 

First you need to find the Vf of one backlite LED that you plan to use.
You need a variable PSU or a current source to make some measurements.
After that tell us how many LED's are used for backlite.

 

First you need to find the Vf of one backlite LED that you plan to use.

After that tell us how many LED's are used for backlite.

LEDs:
~30 @ 3.45V 20mA + (~12 @ 3.45V 20mA or ~12 @ 3.45V 20mA) + (6 @ 2.5-4v 20mA individually switched)

I don't know what else it is you are looking for. The Vf of the LEDs for the backlight is spec'd at 3.45v measures ~3.3 @ 20mA

#of LEDs are:
30, 12 , 1

Please let me know if you were looking for different information, or if I am not understanding.

 

So 3.45V is max Vf or 20mA is maximum brightness ?
How many LEDs for backlite ?

 

Discussions of automotive modifications, and that includes motorcycles, is not allowed according to the terms of service. This thread is closed.