71 Charger Superbee Tribute/Restomod Build

[Rockland71GTX]

You can regulate the voltage down to 5v with a 7508 and then use resistors from there to bring it to 3v.
7805 datasheet voltage regulator IC: Pinout and example circuits

 

[Rockland71GTX]

Here's the link the screenshot is from
DIY Variable Power Supply With Adjustable Voltage and Current

 

[70chall440]

I have 2 power supply's, one is a constant 13.8V and the other is variable down well below 1V, however when I was building my LED boards I used the 13.8V supply to test every section which worked but it evidently put strain some of the LEDs bc I burned one out.

The way I have been doing this is to establish sets of 3 or 4 LED bulbs, each set has a resistor on the back side to allow it to be used with an increase in voltage. The resistor is selected based on doing the math to determine what is required (if you want to know the formula you can google it). I use a LED calculator (many of those online).

My error was using 12V for the input voltage instead of say 14.7. Understand that I came into this with no real experience with LEDs although I have quite a bit of experience with basic electricity. In other words "I didn't know what I didn't know". Some of you might be wondering why this is a deal, well the answer is that if you set up the LEDs for 12V you have to protect them from surges from the alternator which can be around 14.7 when it is on full charge mode. The LEDs will have some tolerance of say 1V or perhaps slightly more but given that I used cheap Amazon bulbs its pretty much a guarantee that a bulb or 2 will die and when they are all soldered in it sucks. By using a resistor that allows 14.7V, when at 12V technically the lights will be slightly dimmer but I do not think by much.

So I have ordered some better quality bulbs and am going to do this a different way which will lend itself better to repair if needed.

 

[mpgmike]

With a 3 volt rating, put 4 in series. This will give you 3 volts per LED with a supply voltage of 12 volts. For 20 ma, just use a 720 ohm resistor per 4-string. In the old days, the common resistor value jumped from 680 to 820 ohms. These days you can get resistors of just about any value you want. As a test, try different sized resistors and notice how a wide range doesn't affect the brightness. In fact, with a 1k ohm resistor, it only slightly dims the bulbs. A 2.2k ohm doesn't dim it all that much more. Better to have a little too large of a resistor than slightly too small.

 

[70chall440]

With a 3 volt rating, put 4 in series. This will give you 3 volts per LED with a supply voltage of 12 volts. For 20 ma, just use a 720 ohm resistor per 4-string. In the old days, the common resistor value jumped from 680 to 820 ohms. These days you can get resistors of just about any value you want. As a test, try different sized resistors and notice how a wide range doesn't affect the brightness. In fact, with a 1k ohm resistor, it only slightly dims the bulbs. A 2.2k ohm doesn't dim it all that much more. Better to have a little too large of a resistor than slightly too small.

@mpgmike
Thanks and this is essentially where I was having problems, I was using a 1 ohm resister per 4 bulbs however after testing the various strings repeatedly I would get a bulb failure ever once in awhile which is a PIA because I was using a breadboard and soldering the bulbs to the board which means I had to remove all that and get the holes opened up to replace a bulb.

However if I build the same panel using 14.7V I would use a 150 ohm resistor and I think I would be much better off in that I would not run the risk of burning up LEDs nearly as much.

What do you think about this?

 

[mpgmike]

The values you used are way out of whack! Please don't take that as an attack, some folks are awesome at HVAC while others are financial wizards. We have that special arena where we love to play. In electronics, there are a couple of "Ohm's Laws" that allow simple math to calculate various things. For example, you want to limit the current flow to 20 milliamps. More than 3 volts/LED is not as important as driving more than 20 ma with LEDs. So, Ohm's Law states that "Current = Volts / Resistance". With 12.0 Volts and 1 Ohm of resistance (regardless of how many LEDs you string in series): 12 Volts / 1 Ohm = 12 AMPS! Put another way, that's 12,000 milliamps (remember, your LEDs are rated for only 20 ma)!

If we take 14.7 Volts and want to target 0.020 amps (20 milliamps), we can work the formula backwards. 14.7 Volts / 0.020 Amps = 735 Ohms. I hope this helps.

 

[70chall440]

The values you used are way out of whack! Please don't take that as an attack, some folks are awesome at HVAC while others are financial wizards. We have that special arena where we love to play. In electronics, there are a couple of "Ohm's Laws" that allow simple math to calculate various things. For example, you want to limit the current flow to 20 milliamps. More than 3 volts/LED is not as important as driving more than 20 ma with LEDs. So, Ohm's Law states that "Current = Volts / Resistance". With 12.0 Volts and 1 Ohm of resistance (regardless of how many LEDs you string in series): 12 Volts / 1 Ohm = 12 AMPS! Put another way, that's 12,000 milliamps (remember, your LEDs are rated for only 20 ma)!

If we take 14.7 Volts and want to target 0.020 amps (20 milliamps), we can work the formula backwards. 14.7 Volts / 0.020 Amps = 735 Ohms. I hope this helps.

@mpgmike

I am not taking anything you say as an attack seeing that this is not my forte. That said, I got my 1 ohm from a LED calculator here: LED Calculator - Current limiting resistor calculator for LED arrays

If I substitute 14.7V for the 12 it tells me that I should use 150 ohm resistors for every 4 LEDs.

This calculator gives me slightly different results citing 120 ohms for an array of 3 LEDs and 330 ohms for an array of 2 LEDS if calculating 12V input. If I change this to 14.7V then I get 100 ohms for an array of 4 LEDs. LED series parallel array wizard

I don't doubt what you are saying and I know that Ohms law is a thing but I got these calculators from guys who build LED taillights for a job so I don't know what to make of it.

Again, I am using white LEDs which require 3.2V and 20ma if this is any different.

My main issue is whether to use 12V or 14.7V in the calculation...

 

[supergluehero]

If you wanted to, you could order your acrylic from sendcutsend with the holes already cut and the panel to shape. Something to consider if your cutting/drilling skills are somewhat questionable like mine.

 

[70chall440]

If you wanted to, you could order your acrylic from sendcutsend with the holes already cut and the panel to shape. Something to consider if your cutting/drilling skills are somewhat questionable like mine.

I didn't know that they did acrylic...

I can cut and drill without issue, I will be using my mil which has a DRO on it to get the holes in the right place. I just have to spend some time to fixture each panel.

 

[70chall440]

So I have kind of hit a wall when it comes to working on the car, there are lots of things for me to do but I just cannot find the ambition to do them at the present. I have been working on the LED taillights some more and have made what I think is progress.

Basically I have developed drop in panels onto which LEDs are attached and wired. These panels will be have some butyl inside the lens and some hot glue on the other side to retain them (the butyl sticks pretty good). This is a bit tedious but I think I have the pattern and plan plus I think that the results will be better overall.

I have decided to use 14.7V in my calculations for what resistors to use because I figure that while 12V might be a more status quo voltage that the lights see, they should not burn out. They might be slightly dimmer but I do not think it will be perceptible.

The green boards are version 1, the black panel is now V2. I did all of the holes on my mill and they are straight and within .0005 in alignment

 

[70chall440]

I have managed to get a little work done in the past few days despite still dealing with the LED issues.

Yesterday I decided to address the antenna mounting. I am using a "semi automatic" electric antenna which allows you to raise and lower it via a switch which I prefer because I can set the height where I want it. There are several issues when trying to retro fit an aftermarket antenna to a classic car not the least of which is the gigantic hole they put into the fender.

I made a spacer of sorts with the angle I needed for the fender chrome ring then I determined that I could make a bracket onto which the antenna can clamp onto. Once the screw is tightened it holds the antenna very securely.

I have not yet raised the mast to see of it is angled or not but I will soon. That said, not like I am listening to AM or FM radio very often, its more of a hole filler and detail.

 

[70chall440]

I also was able to get some more fiberglass onto my trunk divider.

 

[supergluehero]

Don't mind me, just taking notes. An electric antenna is on my wishlist. Is the trunk divider just what's going behind the rear seat or is it something else?

 

[70chall440]

Don't mind me, just taking notes. An electric antenna is on my wishlist. Is the trunk divider just what's going behind the rear seat or is it something else?

LOL no worries. Just an FYI, there are 2 types of electric antennas, the "fully" automatic one goes up as soon as the radio is turned on and it goes WAY up.. IMO they are way too tall. The "semi" automatic one like I have you have to put it up via am included toggle switch.

Yes the trunk divider is just the normal cardboard deal that goes behind the seat but in my case I am planning to mount my subwoofer to it so I need it to have some strength plus I've always hated them in stock form because the cardboard is so flimsy and they like to fall apart. I am also probably going to put sound deadener on the inside (side facing the backseat)

 

[Rennkafer]

Excellent idea on the seat divider! I plan to do similar on the Coronet regarding mounting a sub and amp so that's pretty helpful. I'm also struggling with how to handle the giant fender hole. I keep a cover on the car most of the time and don't want a big hole in it. I won't likely even need the antenna since I also rarely listen to AM/FM (for broadcast it will likely be satellite). May just turn a plug on the lathe and paint it for now.

 

[70chall440]

Excellent idea on the seat divider! I plan to do similar on the Coronet regarding mounting a sub and amp so that's pretty helpful. I'm also struggling with how to handle the giant fender hole. I keep a cover on the car most of the time and don't want a big hole in it. I won't likely even need the antenna since I also rarely listen to AM/FM (for broadcast it will likely be satellite). May just turn a plug on the lathe and paint it for now.

Normally I would just weld a fender washer in the hole and close it off but I decided I wanted to keep the antenna there. Is some cases I make a inset that closes off most of the hole but provides an antenna mounting position. The problem here is that on the Charger the fender has so much angle in that area you basically either have to close it all off or use the stock bits.

I am trying to decide if I want to put more fiberglass resin and/or matt onto the divider or not. Its much better now but not super rigid. I am trying to decide if I want to put the sound deadener on it.

Problem now is the weather!!! as you know, it has gotten cold out and while I do have heaters in my shop I hate to waste the fuel unless I am going to be in there all day.

 

[Rennkafer]

Ya, currently about 21 out here, so a mite chilly. I unfortunately only have one stall to bring a car inside, and it has another project in bare metal sitting in it currently. So all Coronet work is outdoors. Though now it's driving, I have some options for short term stuff as I have a friend nearby with an indoor lift.

I'm wondering on the divider board if it might be better to start off with making a new one from masonite. Might be a bit stiffer than stock to start off with, then fiberglass that.

If I were going to paint the Coronet anytime soon I'd just weld in a piece too, for the time being though it's retaining its lovely patina so a plug is probably in order.

 

[70chall440]

Ya, currently about 21 out here, so a mite chilly. I unfortunately only have one stall to bring a car inside, and it has another project in bare metal sitting in it currently. So all Coronet work is outdoors. Though now it's driving, I have some options for short term stuff as I have a friend nearby with an indoor lift.

I'm wondering on the divider board if it might be better to start off with making a new one from masonite. Might be a bit stiffer than stock to start off with, then fiberglass that.

If I were going to paint the Coronet anytime soon I'd just weld in a piece too, for the time being though it's retaining its lovely patina so a plug is probably in order.

I have a full shop so its not a huge deal but I have to get the heat up a bit to work in there comfortably which typically isn't a problem. I spent about 3 hours in there yesterday without turning the heat on and it was fine, it was like 42 outside.

I have made new ones and that is certainly an option. I once made a divider out of 1/8 plywood, then coated it with fiberglass resin and painted it. Masonite would definitely work, I have found some large plastic sheet at Home Depot that works well, its not super thick but it is somewhat soft and very easy to work with.

In this case I had bought the new divider and chose to go this route. I have to clean it up, mount it and mark where the braces are and then I can mount my sub to use using nutserts. I am going to cover the side facing the seat with sound deadener (I was just researching this). So as I think about it, the side I just put the fiberglass onto will face the seat and be covered with sound deadener, then the clean side will face the trunk and have the sub attached to it.

 

[Rennkafer]

I have a full shop so its not a huge deal but I have to get the heat up a bit to work in there comfortably which typically isn't a problem. I spent about 3 hours in there yesterday without turning the heat on and it was fine, it was like 42 outside.

I have made new ones and that is certainly an option. I once made a divider out of 1/8 plywood, then coated it with fiberglass resin and painted it. Masonite would definitely work, I have found some large plastic sheet at Home Depot that works well, its not super thick but it is somewhat soft and very easy to work with.

In this case I had bought the new divider and chose to go this route. I have to clean it up, mount it and mark where the braces are and then I can mount my sub to use using nutserts. I am going to cover the side facing the seat with sound deadener (I was just researching this). So as I think about it, the side I just put the fiberglass onto will face the seat and be covered with sound deadener, then the clean side will face the trunk and have the sub attached to it.

I do too, but it's an odd deal... my shop (~40'x40') is the lower floor of the house. Previous owner/builder of the place designed it that way, no access from upper to lower floors (you go outside and around back). Has one garage door and a man door. Only an 8' ceiling though... so no lift.

My original divider is in surprisingly nice shape (unlike the parcel shelf), but I think using something a bit stronger to start with (and not 54 years old) is probably the best idea. Plywood had also occurred to me, and that would probably be the strongest base to work from.

 

[70chall440]

I do too, but it's an odd deal... my shop (~40'x40') is the lower floor of the house. Previous owner/builder of the place designed it that way, no access from upper to lower floors (you go outside and around back). Has one garage door and a man door. Only an 8' ceiling though... so no lift.

My original divider is in surprisingly nice shape (unlike the parcel shelf), but I think using something a bit stronger to start with (and not 54 years old) is probably the best idea. Plywood had also occurred to me, and that would probably be the strongest base to work from.

Sounds like an interesting house, shame there is no internal access though. I have 2 40x60 shops, one is my storage/parking area and the other where I work and I still don't have enough room to my liking... Unfortunately I cannot expand anymore on my work shop so I have to live with what I have which is totally fine. Out of the 4 bays I have 2.5 of them available to work in, the other 1.5 bays are filled with metal working equipment (mill, lathe, welding table, etc).

In other words I am complaining about 1st world problems.... lol all is good.