Global Scale Modeller

Happy Saturday Everyone!

I'm currently working on a 1:1200 scale Titanic for my sister-in-law and I'm doin' some figurin' for lighting the lower hull with LED's and putting it into a little dio. Unfortunately due o the construction of the kit, I won't be able to light the upper hull, but someday I'll build the Minicraft 1:350 and resolve that issue. Anyway, I just wanted to get a double check on the wiring before I do any soldering. I used http://ledcalc.com/# for the calculations. I'll be using a 9v battery, slide switch for on/off, 5 LED's @ 3.0-3.2v @ 20mA. Below is my rough sketch of the wiring and the hull layout. I'm particularly questioning the connection of the LED's to the switch and if I have the polarization flipped?

LED Project by Iggy Pants, on Flickr

I'm actually a bit confused. It sure looks like you have + from the battry wired to - on all LED's? But maybe it's a typo?

I think that the battery and switch should be more like this or you will create a short circuit. Sorry the picture is sideways but photobucket doesn't want to work today.

Hope this helps

I assume you want it to look like this?



I don't know how your switch works but if it's a standard one with 3 pins wire it up on either - or + rail. So in this example, wire the middle pin to + and One of the other pins to +. When you move the switch it will open or close the circuit.

RobertK wrote:I assume you want it to look like this?



I don't know how your switch works but if it's a standard one with 3 pins wire it up on either - or + rail. So in this example, wire the middle pin to + and One of the other pins to +. When you move the switch it will open or close the circuit.

Hi Robert, thanks for the reply. It is a 3 pin switch. Do you mean wire the middle pin to + and one of the others to -? Or they both get wired to +? That's the same diagram that ledcalc.com gave me as well. Just not sure on the actual wiring of the +/-'s.

mincemeat wrote:

RobertK wrote:I assume you want it to look like this?



I don't know how your switch works but if it's a standard one with 3 pins wire it up on either - or + rail. So in this example, wire the middle pin to + and One of the other pins to +. When you move the switch it will open or close the circuit.

Hi Robert, thanks for the reply. It is a 3 pin switch. Do you mean wire the middle pin to + and one of the others to -? Or they both get wired to +? That's the same diagram that ledcalc.com gave me as well. Just not sure on the actual wiring of the +/-'s.

The middle pin to + and one of the other pins to + aswell. So, you will use 2 out of 3 pins. If you wire in the - with + you will short the circuit, that's bad

So, if red cable is +, this is how you should wire the switch.

RobertK wrote:So, if red cable is +, this is how you should wire the switch.

OK, I think I understand. Here is the updated diagram. Looks a lot cleaner with actual straight lines. Please let me know if I understood correctly.

2016-09-25_08-16-44 by Iggy Pants, on Flickr

That looks right to me

Thomas2542 wrote:That looks right to me

Thanks Thomas!

RobertK wrote:So, if red cable is +, this is how you should wire the switch.

Thanks for the help and support Robert!

This looks right to me!

http://www.hebeiltd.com.cn/?p=zz.led.re ... r#parallel
This place rocks when it comes to LED circuits
Have fun !

series / Parallel / singles... enter values and Voila !

take care.

schweinhund227 wrote:http://www.hebeiltd.com.cn/?p=zz.led.re ... r#parallel
This place rocks when it comes to LED circuits
Have fun !

series / Parallel / singles... enter values and Voila !

take care.

Thanks! I'll be sure to bookmark it!

I have only one concern with the wiring diagram here. The LED's are drawn / installed the wrong way round and the resistors therefore don't make sense to me.

Vleugelmoer wrote:I have only one concern with the wiring diagram here. The LED's are drawn / installed the wrong way round and the resistors therefore don't make sense to me.

So what your're saying is that, the LED's polarization needs to be flipped?

Yup. If I remember correctly from electronics class in college all diodes are installed "blocking" opposing the current flow. That being said, it's not possible to install two diodes in series with eachother. I'll see if I can find you a website explaining it all in easy to read language.

You can use LEDs in either series or parallell.
So, everything looks alright to me.
The typical LED have one long and one short pin. The longer pin is +, just wire it up as you planned and it will work assuming you have the correct specs of your LEDs and calculated everything correct.