Bought a car, primitive in its own right but I like it. 1995 Lexus GS300. The car came with worn out luxuries such as badly dried and cracked leather seating and brittle plastics in the dash vents. It also came with it's own little annoyances mostly electrical like the radio I later discovered didn't work because the constant wire somewhere between the fuse box and the head unit is burnt out or broken or (you name it, being 23 years old) whatever etc. Also noted that the interior lighting such as the map lights, vanity lights, the personal and foot lighting do not work for the same reason. In my mind likely the same wire. Since I haven't had time or space to take the ENTIRE dash apart I have done motor modifications to replenish some of the luxuries this vehicle once had. I bought nice plush seats from a local junk yard for $63 from a 2nd Gen GS300 (2002 to be exact) one of them was easily wired in but the driversd seat had a memory module and being limited in my electronics knowledge I was able to bypass all of that "mess" and just mount my old switches to the new seat. (Not altogether horrible and awesomely comfortable compared to the previous driver's seat) I found a CD Changer on eBay that still works and bought it! So I'm not in the middle of trying to find the time to repoace the door speakers and rear deck "subwoofer" as well as the amplifier that came with the car with an aftermarket since the values of the stock amp don't match well with other aftermarket speakers and the audio in my vehicle is high priority. I'm sorry it's taking me all of that to get TO THIS:

THE PROJECT:
Where the digital clock once was is now an empty canvas. But like I said my electronics knowledge is limited to say the very least. This next paragraph will prove that point.
I would like to put two USB charger ports mounted one atop The other preferrably as well as a voltmeter I purchased on Amazon (to provide me with auto battery voltage only) and I also have a box of 150 small and smaller individual LED lights. Now I know what most of the different electrical components do, but it's the mathematics that I'm most definitely unsure of so for that reason I come here to ask for any and all help I can get.
I didn't honestly plan on asking for help but there point of this project is two fold, lol, one is to have a unique piece in my vehicle that I can be proud of AND to learn more about something I've always been fascinated with. I could likely make all of the previously mentioned devices coexist and even charge a couple of phone's, light up an LED while charging and even give me a voltage reading of my battery but in the end i would know how to do only that and likely only in that one circuit or circuits and in that one layout. I would much rather actually learn why and how I do it so as to lay a base of working electrical knowledge down to build upon going forward.

I also bought some 3.5 female plugs so I can solder an auxiliary input into my cassette player heads like I saw on YouTube, but that I think I can handle unless someone has some ideas on that project too. I realize that I gave you no values on anything yet but just trust that I am doing this with the most basic of electronics. I will come back and answer any questions as I get them. If anyone actually wants to help an old dude learn something likely taught in elementary school now.
Here is a pic of some of the components I plan to use. At first my thought was to just wire a 12volt dual USB charger into the thing (and I still might) but that doesn't solve the issue of the voltmeter it the LED that lights when charging via USB. Keep in mind this car has that constant voltage issue so the only source of power I have at this spot is already switched so it will only work when the key is on accessory or the car is running. I can always run another constant wire over if I still haven't found the burned out hot wire wherever it may be but until then just be aware of that so there's no need in trying to think about the two different values of current flowing at this spot in the dash. Thank you all in advance for even reading this far into my dilemma. That alone proves either you care or you're curious or you like watching peolpe in misery and enjoy watching them squirm as it deepens. With all sincerity. -Deaner

 

Too long, didn't read. Perhaps you could offer a condensed version.

 

Welcome to AAC. Doesn't sound like you are in misery - just excited about your new wheels. Just a suggestion, but maybe pick one clearly defined project (hopefully not with LEDs or cassette tape players) and tell us about what you are doing or trying to do or want to do? It's hard for me to follow, you sound like me after about 800 mg of caffeine, but I like your icon

 

Lol thanks Raymond. It is truly going to be a lengthy prosess and this I'm afraid is really going to be easy compared to the learning that I'm going to take on after I move into my new house. My plan is to build a motor for it (my first) and drop it in. I can see that being a massive headache already.
Ok the project I'm planning is starting like this.
I've got a sheet of ABS that I plan on cutting out the 3" x 0.75" (roughly) piece from. The dimensions I just gave are what is truly visible from the front of the trim piece. The whole piece is bigger but I've got that planned out so that I am going to use the original clock piece in order to make this piece snap in and out. All of this is really trivial but it is where I'm planning on putting the chargers with an LED that illuminates when I plug into either of the two.

Would it just be best (I realize it would be simplest most likely) that I just use a USB charger from one of the tens of USB chargers I have in hand already? When looking at the USB plugs for a board those connections just look so tiny and that for me would be a huge challenge. I'm not opposed to challenge but I would rather not burn through $100 worth of USB ports trying to get two mounted and working correctly. I realize that is cheating myself out of the knowledge and challenge of knowing the USB (charging aspect anyway) but is that even something I should care about. I mean who knows next week we could be using a whole new technology (though not likely) but where else will it benefit me except maybe perfecting my soldering skills.

Sorry, I got wordy again. I do that often. I spend around 50-60 hours on a computer all week working with that car downstairs and the web browser icon staring me down daring me to waste some of that valuable work time so when I finally get a minute on the weekend I have to pack as much time as I can into my little pet project.

Thanks for the attention. I'm definitely lost and would rather make this a simple and cheap modification. Like it honestly should be.

So.. usb, and LED that lights when charger used on a 12v system.

 

With a pot of LEDs, you might be using singles, 2 in series, 3 ( white, blue ) in series,& 4,( red ) .
Small differences add up in series connections, so I measure forward voltage of all LEDs & put them in cans of = V. Make up strings of approx. = V, a low V with a high V & a average V. With a 12 V power supply use a 470 or 510 ohm resistor in series with LED under test. Connect a white & red LED in series both across test strip to limit test V if LED UT is connected reversed to limit rev. V to about 5V.

 

Welcome to AAC!

Sorry, I got wordy again. I do that often.

Wordy isn't much of a problem if you use paragraphs to organize your thoughts and put whitespace between the paragraphs.

Your first post was too dense. "Wall of text" as another member puts it. I didn't read more than the first few sentences.

 

Welcome to AAC!

Wordy isn't much of a problem if you use paragraphs to organize your thoughts and put whitespace between the paragraphs.

Your first post was too dense. "Wall of text" as another member puts it. I didn't read more than the first few sentences.

Enough Said...

 

I spotted white space.

I mean I didn't double tap the enter key every single time I finished.....

a....

sentence......

I was thinking in paragraphs though. My error. Don't sweat it.

 

Condensed VERSION..


One LED

Two USB

One Voltmeter...

In Car...

Dash...

Ideas? Thoughts?

Very least,
For standard LED's (I have both 5mm & 3mm) what size resistor would I need using a 12V car battery as power source?

LED Colors? I have BLUE, WHITE, GREEN, YELLOW... If that makes any difference.

Voltmeter? See below for all the information I have.

Thnk U L

 

With a pot of LEDs, you might be using singles, 2 in series, 3 ( white, blue ) in series,& 4,( red ) .
Small differences add up in series connections, so I measure forward voltage of all LEDs & put them in cans of = V. Make up strings of approx. = V, a low V with a high V & a average V. With a 12 V power supply use a 470 or 510 ohm resistor in series with LED under test. Connect a white & red LED in series both across test strip to limit test V if LED UT is connected reversed to limit rev. V to about 5V.

Thanks B,

I appreciate the help. I was under the impression that like other forums somebody would care about a "why I'm here" kind of deal, but hey I'd rather skip right to the meat of it all too.

Thanks again,
Dner

 

Too long, didn't read. Perhaps you could offer a condensed version.

Note the Condensed version. Non-Reader's Digest, if you will.

Thnx

 

By the way is there a "bird" hand gesture emoji on here somewhere I'm missing? I'd sure like to find it.

 

What current rating do you want on the USB charging ports? What voltage do you want to display? 12V or 5V? Selectable? What voltage and current is the cassette player? What is the purpose/function of all the LEDs?

 

Your condensed version wasn't helpful. I bit the bullet and read your first post.

The second paragraph described your project.

If you want it to be something you'd be proud of, using that dual USB cigarette is going to look like a hack. If I was to do something like this, I'd make a faceplate that fit well in the opening. I'd find a way to disassemble the USB thing you have to make them look like they were designed for the faceplate.

You're not going to be able to measure the battery voltage of anything you're charging. And the USB charging devices don't have a charging indicator.

Displaying the car battery voltage (when the vehicle isn't running) or the regulator voltage is more realistic.

For standard LED's (I have both 5mm & 3mm) what size resistor would I need using a 12V car battery as power source?

LED Colors? I have BLUE, WHITE, GREEN, YELLOW... If that makes any difference.

Color makes a difference because forward voltage is different for each color. We also need to know the maximum DC current they're designed for.

The most common way to power LEDs is to use a current limiting resistor. If you use multiple LEDs and you want them to appear to be the same brightness, you need to use a current source; because the forward voltages of the same color LED from the same batch isn't tightly controlled.

 

I would use the charging V, about 14 V, for figuring LED resistors. Vf= forward voltage of LED.
White, blue, aqua LED with Vf of about 3V operating on 10 mA; 14V - 3V = 11V / .01mA = 1.1k = 1k1.
Red, yellow about 2V, to know, measure. If 3 whites in series =( 14 -9 ) / .01 = 500. Choose an operating current that is pleasing, 5 mA to 20 mA.

You could use a LED bar graph for 15V another for 6V, LM391. Different colors different points of interest.

For 5V use adjustable current, voltage buck converter?

 

Why not get something like this?
https://www.amazon.com/Digital-Volt...r=8-3&keywords=buck+converter+with+volt+meter

It displays the input (battery) voltage and the output voltage (to fine tune it). It can handle up to 3 amps. That is a safe margin for two standard 1 amp USB ports.

Also, you can get one like this and just use the volt meter you have.

 

To monitor USB charging , a simple circuit that detects a V drop across a diode could be used. Diode is inserted between supply & buck converter + input.

 

To monitor USB charging , a simple circuit that detects a V drop across a diode could be used. Diode is inserted between supply & buck converter + input.View attachment 156150

What about a shunt and op-amp and comparator? You could also add one comparator to detect current and another to prevent a short, and more to get an LED bar indicator of current. The issue with a diode is that is wastes power and if you have a 5V converter it's now a 4.4V converter (for silicon).

 

Why not get something like this?
https://www.amazon.com/Digital-Volt...r=8-3&keywords=buck+converter+with+volt+meter

It displays the input (battery) voltage and the output voltage (to fine tune it). It can handle up to 3 amps. That is a safe margin for two standard 1 amp USB ports.

Also, you can get one like this and just use the volt meter you have.

Lol
That's so funny that you picked THAT PARTICULAR CHARGER!! that's actually the one I bought to do this project. My only issue with it is... It's made out of metal. I think it's aluminum maybe, but wherever it is it's not going to be very easy to disassemble.

Also, I'd like to be able to put a larger voltmeter or even something like you showed but the display alone is too large for the spot I've got to put it so I'm kinda limited.

Thanks so much for saying something. Any and all help is appreciated. I can take constructive criticism, but if you can dish it you shouldn't scoff when you get served. Your help is greatly appreciated and honestly makes me rethink my project. Maybe I'm not cutting corners doing it the easy way. Maybe it's easy because it's the easiest. F it right!? Why make life hard on myself?

 

What current rating do you want on the USB charging ports? What voltage do you want to display? 12V or 5V? Selectable? What voltage and current is the cassette player? What is the purpose/function of all the LEDs?

BR-549... Made good music too as I recall. It's not just a phone number anymore!

Anyway... Pick an amperage! My car is 12 volt I'm American and we have mostly 12 volt systems as far as the ones I've owned. Maybe in 2018 that's different but the car is a 23 year old antique. I do realize that the USB charger is a 5 volt system but I'm looking for how or the best way really to get that 12 down to the needed 5 etc.

S#*t you asked about the casette player too didn't you? It is 12v. Got a 12v constant and a switched 12v on the accessory circuit.

Yeah.. my first post.. the basis of this thread shows that the LED is to show that the USB (s) are in use.

I've not purchased another USB for this but if I get the right answers I can get whatever I should to make this safe and actually work as well as fit in the small space I have for it. I have plenty of old usb chargers so I could and likely will use one after looking at livewire's post. Might as well right?