LED CIRCUIT DESIGN VIDEO

[Ace-Garageguy]

Over the past decade, quite a few people have asked about using LEDs to get working lights in their cars.

Here's a good basic introductory overview, a great opportunity to start learning something new as a spinoff from building models.

EDIT: My own introduction to electronics came way back in the late 1950s, in the pages of Model Railroader. It kindled an interest I've expanded on since then, one that has allowed me to do lotsa cool stuff and make not-a-few bucks.    

 

 

Edited January 3, 2022 by Ace-Garageguy

[deuces wild]

I picked one of these battery operated closet lights which are LEDs for only a buck at Dollar Tree... They have 2 LEDs with the printed board and they use 3 button type batteries.....

These are easy to take apart with only one micro screw... I  already gutted this one out but I  plan on buying more....

Edited January 4, 2022 by deuces wild

[Ace-Garageguy]

3 hours ago, deuces wild said:

I picked one of these battery operated closet lights which are LEDs for only a buck at Dollar Tree... They have 2 LEDs with the printed board and they use 3 button type batteries.....

Smart move. A cheap way to get multiple LEDs and a printed board. Most you'll usually need to do is lengthen the leads to the individual LEDs.

Downside is that the quality of the components can be awful, and they'll sometimes fail in days...if not minutes.

But for a buck, it's a decent gamble.   

[deuces wild]

??

[peteski]

If you can pick up some warm white LED Christmas tree lights after the holidays (50% off sale), they are a good source of standard 3mm or 5mm LEDs.  The lens might be oddly shaped, but you can file it down until it is flat (the clear material is epoxy resin). Just don't file it down too close to the LED chip inside.

[deuces wild]

Another way to light up a model is with fiber optic strands and a light box... of some sort..

[peteski]

9 hours ago, deuces wild said:

Another way to light up a model is with fiber optic strands and a light box... of some sort..

That works for certain applications, but the light coming out of the end of a fiber is quite directional (like a focused beam out of a flashlight).  LEDs (the small SMD type) have much wider viewing angle, more like a standard light bulb.  And as you mentioned, fiber optics require a enclosed source of light (which can be an LED or an incandescent bulb).  I've used both methods in some of my models.

[Phirewriter]

Thanks for the post Bill. I mess around with Sci-Fi kits, slot cars of various scales as well as automotive subjects and am always looking for lighting ideas for models that don't have lighting kits or to further enhance available kits.

[Ace-Garageguy]

14 hours ago, Phirewriter said:

Thanks for the post Bill. I mess around with Sci-Fi kits, slot cars of various scales as well as automotive subjects and am always looking for lighting ideas for models that don't have lighting kits or to further enhance available kits.

These 1.8 mm 16-18V LEDS are available on eBay (in several colors) for cheap, and include pre-wired resistors.

1.8 mm is less than a scale 2" in 1/25, so they're small enough to work in some side-markers, parking lights, dome lights, instrument cluster lighting, etc.

There are others even smaller.

I've had good luck with them so far, with only about 5% being inop.

A bonus is that the extra-long pigtails on some of them are perfect for correctly-scaled ignition wires in 1/24-1/25 (with the heavier pigtails being good for scale battery cables).

 

Edited January 8, 2022 by Ace-Garageguy

[peteski]

Smallest available LEDs are SMD 0201  (that is 0.020" x 0.010")!  You can buy those pre-wired on eBay.  I plan to use those in some of N scale (1:160) model railroad projects.   Next up are SMD 0402 LEDs (as you would expect, they are 0.040" x 0.020").  All LEDs are available in multiple colors of course.

[peteski]

Here is a chart of common sizes of Surface Mount Device (SMD) package footprints.  It is common among all the SMD devices (resistors, capacitors, LEDs).  These dimensions are of the footprint. The height is not described as it varies between  different components.  You can also see how the size (the 4 digit code split up into two 2-digit numbers)  relates to the actual dimensions in decimal inches.  I figured that this will be helpful to  decide which LED is best suited to your project, so then you can look for that size on eBay.

Edited January 14, 2022 by peteski

[Ace-Garageguy]

2 minutes ago, peteski said:

Here is a chart of common sizes of Surface Mount Device (SMD) package footprints...I figured that this will be helpful to  decide which LED is best suited to your project, so then you can look for that size on eBay.

Great additional info, much appreciated.