Need a schematics

[amiklic1]

Hello everyone. At firs, I wish to say hello to all of you, as this is my first post here (newbee).

What I'm trying to do is to make a LED navigation light for my boat. As I'm not very experienced in electronics, I am asking for a help.

As I understand until now, I need a kind of a regulator. My navigation lights are different in size (from 16*white LED, 3*6 LED /Red/Green/White, 12LED Green or Red), 12*Yellow LED), and they all have a different run voltages, I found this difficult to decide by myself.

Can someone point me to some schematics and explain the basics of how to solve this problem. I would like to connect, let's say, 2 LEDs in series, and than 6 such strings in parallel (for 12 RED or GREEN...). Than, I was thinking to use some voltage regulator (like 78xx series) for voltage regulation. But I don't have any for current reg.

Someone pointed me to PWM regulator, as it's (is it) more effective.

Also, I need a yellow light to be a hazard one, and it has to flash every 2 seconds.

Please help.

 

[amiklic1]

I cannot believe that noone is able to give just a bit of a help.

C'mon guys, I just need that. And, of course, Merry Christmas!!!

 

[koala]

Input voltage? Your on a boat? I am guessing 12V or 24V?

Red, Green, White they have different input voltage. What sort of LED is that? 5mm or x Watt Luxeons?

PWM has higher efficiency if your input voltage alot higher or lower than the LED voltage.

Is there a commercial unit which you could make example of? It's much easier to follow a proven design if you got totally no idea. Then based on the working idea you can slowly improvise the functionality and evolve into a new design.

 

[amiklic1]

OK! Finally one answer.

Here it is: It's 12V system, but my other boat is 24V system.

I'm trying to make something like at www.lopolight.com , but with 5mm LEDs (ordinary ones, not xx Watt Luxeon drivers)

Their design is (for tricolor, red, green, white, 3mm LEDs):

Supply voltage 10-32 VDC
Power consumption 5,6 Watt;
Current @ 12 VDC: 0,5 A:
Current @ 24 VDC: 0,25 A
Light colors Green – Red –
White Intensity >5,4 cd
Visibility (@K=0.8) 2 nm
Number of LED's 109

As the price of their lights is a way too big for me, I'm trying to make something near that. I have a lathe and all necessary tools, but my problem is electronics.

Here are the details of the LEDs I plan to use:

White:
Ultra High Intensity Rating:40000mcd+
Emitted Colour : White
Forward Voltage (V) : 3.2~3.4
Current(I): 20 - 25mA
View Angle: 25 degree
Size (mm) : 5mm

Green:
Emitted Colour : Green
Size (mm) : 5mm
Lens Color : Water Clear
Peak Wave Length (nm) : 520~525
Forward Voltage (V) : 3.0~3.3
Current(I): 20mA
View Angle: 25 degree
Luminous Intensity: 13000mcd

Red:
SOURCE MATERIAL:InGaN
EMITTING COLOUR:RED
LENS TYPE:WATER CLEAR
LUMINOUS INTENSITY-MCD:14000
REVERSE VOLTAGE:2.7 V
DC FORWARD VOLTAGE:1.9V TYPICAL/2.2V MAX
DC FORWARD CURRENT:20~30mA
VIEWING ANGLE:+/-20deg
Size (mm) : 5mm

I hope I can use that ones, s I allready have them.

Thanks in advance

 

[Robban]

I cannot believe that noone is able to give just a bit of a help.

C'mon guys, I just need that. And, of course, Merry Christmas!!!

You barely gave people one day, during christmas, to help you (for free) and you're upset? That attitude wont get you far, just so you know...

 

[koala]

amiklic1 could be rushing for a project? And a new member too... Your question may get more replies if a mod can move it to Electronics forum.

 

[amiklic1]

I'm sorry if I offend someone, and I'm not rushing a project. I have plenty of time to study this issue, but I'll make something out of it, for sure.

I just tried someone to point me to the problem solution, to some schematics, some web page atc.

And, i'm still waiting for that...

Anyway, thank you for help, previous, present and future.

 

[amiklic1]

OK, guys. I have other thoughts right now. I found out the good regulators in Germany, and I'm worrying about other things.

It's stated that the lights I plan to "clone" are:
- 10 to 32 volts input (I solved that one with the driver)
- 0,8 Watt power
- Current draw / 12V = 0,07 A
- 11 green leds
- light intensity >1,2 cd

Ok. Does it mean that there is >1,2 cd on some distance and on some area, or the entire lamp has a LED power of >1,2 cd. They use 3mm LEDs. Hi-bright must be, not emmiter power LEDs.

How to find out which power and intensity LEDs I need to clone this one?
Maybe by current and voltage? It seems as a best way for me, but the ratings are not allways precise nor true.

And how to connect 11 LEDs? It must be one string in series.

 

[koala]

I can't help you regarding the brightness, but yeah connecting the 11 LEDs in series is good, you only need one current limiting resistor if you can't control your regulator current.

In your previous post you have your Green led Forward Voltage 3.0-3.3, so typical I would say 3.2V. 11pcs in series makes it 11x3.2V = 35.2V@20mA output. What sort of regulator are you using? You may need a boost or a charged pump led voltage driver.

 

[amiklic1]

Input voltage to the driver (regulator) is 10-32 Volts, and that's waht Lopolight is claiming, also.

I can't figure out that.

If we realize that any 78xx voltage regulator is regulating the voltage if the input is minimum 3V above output (So, for 6 V output you need at least 9V input), it seems that they could use 6 times two LEDs in series, and the lack of one LED to replace with one ordinary diode, just to help in voltage drop in that circle.

They are using 11 green LEDs for 112,5 degrees light. It must be 15-20 degrees LED.

In their RED light, they use 20 red LEDs, with the overall lamp power the same (0,8 Watt), intensity is the same (>1,2 cd) and the same current (0,07 A/12V). Input range s the same. 10-32 Volts.

Is that all just a marketing trick? It doesn't seems like that as they are very known and reliable manufacturer, and their products are used on very high quality and renown boats.

But I can't figure out the LED configuration and intensity issues.

 

[TorchBoy]

If you're going on a 12V marine lead acid battery you don't actually need a voltage regulator. A common arrangement is to drive a string three green or white LEDs in series with a 150 ohm resistor. Use four parallel strings for a total 12 LEDs of that colour. For the red LEDs you could do five in series because they have a lower forward voltage. Again, use four parallel strings for 20 LEDs.

I find http://ledcalc.com is useful for playing with figures and multi LED setups. LED Calc example:

Supply Voltage
13.2 VOLTS (or 12V)
Voltage Drop Across LED
1.9 VOLTS
Desired LED Current
20 MILLIAMPS
How many leds connected
20

And it draws a cute little diagram of what it will look like. So there's your configuration. Edit: And schematics, and the resistors do the current limiting (regulation). So it's all sorted.

:welcome:

 

[TorchBoy]

BTW, using only five red LEDs in series instead of six will provide a bit of stability in LED brightness as your battery slowly flattens.

BTW also, if you use a 78xx voltage regulator (or an LM317 set up as a current regulator) so you can use the same lights with your 12V boat or your 24V boat then it'll just be burning off the extra volts as heat. Not very efficient.

 

[amiklic1]

I know that excess voltage is going to heat.
But the resistor is heating, also, and it does not seem as a reliable solution to me. Why Lopolight is using the electronic driver if the resistor is the best solution?

You can see their driver at
http://www.yacht.de/schenk/n003/elektroupdate.html?PHPSESSID=06979727261e6cd5f45fff58de7bf6a3
, just scroll down a bit. That's early model of their lamp, in new models the epoxy is black, so nothing is visible inside the lamp.

 

[TorchBoy]

But the resistor is heating, also,

Forward voltage of white LED is average 3.3V. Three in series and that's 9.9V, leaving at the most 3.3V that needs to be dropped by the resistor. Running 20mA it'll dissipate 66mW, which means it won't even get warm to the touch. In fact, touching it will probably heat it more. So it's not a problem.

and it does not seem as a reliable solution to me.

Only if your soldering is bad.

Why Lopolight is using the electronic driver if the resistor is the best solution?

Two thoughts come to mind.

1. To justify them charging mega-euros for it.
2. So that it can be put in (on?) a 12V or 24V boat as needed.

Using resistors does sound like the best solution for you, as long as you set it up for either 12V or 24V. (Actually you could use just a 12V setup and use a single large resistor to drop the other 12V when using it with a 24V supply, but that would halve its efficiency straight away.)

If you do want something you can swap easily, and run on either boat, then a linear regulator would be one way to do it, but your efficiency will be about 2/3 what it would be using resistors at 12V, and 1/3 that efficiency when running the thing on 24V.

You can see their driver at
http://www.yacht.de/schenk/n003/elektroupdate.html?PHPSESSID=06979727261e6cd5f45fff58de7bf6a3
, just scroll down a bit. That's early model of their lamp, in new models the epoxy is black, so nothing is visible inside the lamp.

They look like really nice lights, but boy it's complicated inside. Remember that complexity does not always mean reliability. Lopolight makes high quality lights (IP68+ rating!) but if you make something complex yourself there's a greater chance of something going wrong. :sigh: There is a principle known as K.I.S.S. which stands for Keep It Simple Stupid. The simpler the better, and the more reliable it's likely to be.

 

[amiklic1]

That electronics in Lopolight is not so complex. You can see something allmost similar on http://www.a1w.de/html/hko_.html, and the prices are OK.

I just need a way to figure out their ratings.