Need help upgrading power source

skorpiyun · Post by **skorpiyun** » Thu Jun 07, 2012 12:25 pm

Hey all. Sorry if this is a dumb question, but i just really get confused and overwhelmed when it comes to figuring out lighting. I have tried to read up on this stuff, but it just seems to be beyond my comprehension.
Anywho, I just finnished this cruiser:
http://i608.photobucket.com/albums/tt16 ... tinga6.jpg

http://s608.photobucket.com/albums/tt16 ... tinga5.jpg

http://s608.photobucket.com/albums/tt16 ... tinga2.jpg

http://s608.photobucket.com/albums/tt16 ... tinga3.jpg

http://s608.photobucket.com/albums/tt16 ... tinga4.jpg

As you can see, I was able to blunder my way through getting it lit, however, I would like to change the power source, (if it is even possible?)
Right now, I have 9 LEDs in it. there are set up in clusterers of 3, with a 9V battery powereing each cluster, (3 9V batteries total.) So...I mean...it does work....but the batteries go dead fairly quick. If I plug all of them in, with 24-48hrs, the batteries are pretty muched used up, and all the lights get pretty dim.

So, my question is this: Would it be possible for me to rig this up so I can plug it into the wall, instead of using the 9V batteries??? Currently, all my wires run down through the support tube and out the bottom, so I can get at those, but the LEDs & resisters are pretty much innacessable unless I tear the model apart,( which I really don't want to do.) I have been looking into Wal-Wart, but don't know if that would work or not?

Again, sorry if this is a stupid question, but I don't know who else to ask?? Much thanx in advance.

D

Paulbo · Post by **Paulbo** » Thu Jun 07, 2012 4:57 pm

They make 9V wall warts. 9 LEDs should be no problem to all be run off a single unit.

Mr. Engineer · Post by **Mr. Engineer** » Thu Jun 07, 2012 10:06 pm

Yep. Agree with Paulbo. But I need to ask you some questions.

1. Wall adaptors have a range from 500mA to about 1A. So, assuming your circuits are correct, it would not heat up.

2. Also, I have to assume you are using White LEDs which runs on 3 volts each and you therefore put them in series with a resistor to match the 9 volts. Then you stuck fibre optics on them and tinted them with clear blue or red for the desired effect, right?

I am not an expert on this model nor have I ran an LED beyond that long but the thought (#2) just came to my mind and I am therefore curious about the battery's lifespan. In theory, from this website (http://led.linear1.org/led.wiz)

The source voltage: 9
diode forward voltage: 3
diode forward current (mA): 25
number of LEDs in your array: 10 (just example)

The current consumption is 100 to 125mA.

Then when you go to sites like these:
(http://oregonembedded.com/batterycalc.htm)

Capacity of battery rating: 565 (for your 9volt)
Current consumption during sleep: 0.0001
Current consumption during wake: 125
No of wakeups per hour: 3600
Duration of wakeup time: 1000

You will get 0.16 days, which is 3.84 hours, which, if you connect more 9v, might last you longer. Hmmm.. this is interesting.

skorpiyun · Post by **skorpiyun** » Thu Jun 07, 2012 10:58 pm

hey, thanx alot for the help fellas!!!!!!! So maybe something like this would work for me????

http://www.sparkfun.com/products/298

Engineer: your #2 comment is pretty close, except the red LED's. I have 3 reds in one circut powered by a single 9V battery. one for each engine, and one in the intake grill on the top. the red ones seem to drain the batteries much quicker than the white ones. I dunno if that would affect using the walwart or not...if the reds would take too much juice away from the whites???

I think...what I might try, is get that 9V wal-wart, and then make a second set of LEDs, (exactly the way I have it set up in my model,) and try it out. The last thing I wanna do is fry the LED's in the model, cause I would have to rip the whole thing apart to replace them, and no way I wanna do that!!! If I have a second "experiment set", big deal if I fry those!! LOL I guess I kinda put the cart before the horse with this build, but I will know better for next time!!! LOL

Thanx again fellas!!! Really appreciate the input!!
D

Scott Hasty · Post by **Scott Hasty** » Thu Jun 07, 2012 10:59 pm

As many have read, I am a HUGE opponent to 9V batteries. Their current capacity (as stated) is woefully low; the only modern use for them I can think of is in DC operated smoke detectors.

As far as connecting them together, BE CAREFUL. If 3 are wired in series, that would apply 27 volts to your circuit...POOF.

This supply has plenty of output current for most needs:

http://www.jameco.com/webapp/wcs/stores ... 1952847_-1

skorpiyun · Post by **skorpiyun** » Thu Jun 07, 2012 11:06 pm

Thanx scott!!!!! I think I might try the one you suggested with my "experiment set" of LED's, and see what happens!!

Mr. Engineer · Post by **Mr. Engineer** » Thu Jun 07, 2012 11:09 pm

I wonder if, instead of connecting directly to the wall adaptor directly, if it connects to a PWM output might save on the power?

Just thinking out loud as I have not tried PWM yet...

Reason I am thinking about this is because I have to assume (*again*) that the model is all sealed up. But as far as I know, red LEDs, with their 2volt and at least 20mA consumption, is quiet OK. Its the White and Blue LEDs which eats power like there is no tomorrow. But I just hope that they are not connected in series with your Whites as this will most likely kill them.

skorpiyun · Post by **skorpiyun** » Fri Jun 08, 2012 12:04 am

Mr. Engineer wrote:
Reason I am thinking about this is because I have to assume (*again*) that the model is all sealed up. But as far as I know, red LEDs, with their 2volt and at least 20mA consumption, is quiet OK. Its the White and Blue LEDs which eats power like there is no tomorrow. But I just hope that they are not connected in series with your Whites as this will most likely kill them.

I have one series of 3 whites with resister powered by 9v. another series of 3 red with resister connected to 9v, and the bridge has 2 white and one red with resister powered by 9v. Sounds like I might have trouble with the bridge lights huh??

Mr. Engineer · Post by **Mr. Engineer** » Fri Jun 08, 2012 12:09 am

Good Lord!

You're right! can't mix LEDs of different colours. In fact, sometimes, you can't even put the same colours in series eitehr as different batches have slight variations. But in modeling, just don't mix them.

I had my first catastrophe when I mixed red and green on the 90's for a TOS Enterprise and well.... my 15 minutes of fame lasted very much less than that.

skorpiyun · Post by **skorpiyun** » Fri Jun 08, 2012 12:11 am

maybe I can leave the bridge lights, which is a mix of white and red with a 9v battery, and the the other two, (which are 3 whites on one circut, and 3 reds on the other) I could hook up to the Wal wart. At least then I am only burning through one 9v battery instead of 3!!!!!!! LOL

Thanx again fellas for your comments and helping me out with this...I know it must feel like you're explaining stuff to a 6 year old!!! LOL

Mr. Engineer · Post by **Mr. Engineer** » Fri Jun 08, 2012 12:17 am

OK, here is a very painful and personal question you must ask yourself:

Is it better to rip out the bridge and redo the circuit NOW, or suffer with two different power supplies (plus other hidden problems) in the long term?

I had to ask this to myself everytime I do one. And until now, I do not have the heart to glue them all shut while the electronics are in there. But I might, for the first time, when my friend tries my Cylon Raider circuit here (sorry to hijack the thread):

http://www.starshipmodeler.net/talk/vie ... hp?t=99530

And more here, in our local Forum:
http://z12.invisionfree.com/ScaleModels ... topic=9304

skorpiyun · Post by **skorpiyun** » Fri Jun 08, 2012 12:17 am

OR......actually, that one red that is wired in with the other two whites, is the only LED in the whole model that I might be able to get at without too much trouble!!!!!!!!!!!!! I'll pop the top of the bridge off, pull out that red one, and re-solder in a white one!!!!!!!!!!! I have a red plexi pannel in the bridge that the light goes through anyway...so I really don't need a red LED in there!! There is hope!!

D

Paulbo · Post by **Paulbo** » Fri Jun 08, 2012 6:38 am

9 volts is 9 volts is 9 volts.

If you're running things on 9 volts now, they'll work on 9 volts tomorrow. Whether you're using 3 separate batteries or a wingle wall wart with your circuits running in parallel to each other, you're still running at 9 volts.

You're really overthinking this.

skorpiyun · Post by **skorpiyun** » Sat Jun 09, 2012 12:05 am

Ordered the 9V wal wart recomended by scott today, so hopefully next week can finnish this up. I know I sound like a broken record, but thankyou so much everyone for your input/advice!! Means alot!!
D

en'til Zog · Post by **en'til Zog** » Sun Jun 10, 2012 1:00 am

I'd like to suggest using a 9 volt REGULATED wall wart only.

UN-regulated power supplies put out a lot more than their "rated" voltage if they are not being run at close to their max rated amperage.

Regulated supplies are forced to put out only their rated voltage no matter how much amperage you are using. (Up to their max amp ratings, anyway.)

hth

Scott Hasty · Post by **Scott Hasty** » Tue Jun 12, 2012 12:32 am

en'til Zog wrote:I'd like to suggest using a 9 volt REGULATED wall wart only.

VERY good point. I cannot point out how many people order these things, unregulated. But I'd never steer a brother wrong. My linky is for a regulated wart...

skorpiyun · Post by **skorpiyun** » Wed Jun 13, 2012 3:40 pm

I was hoping you would say that Scott!!!

Should be here tomorrow. Will let you guys know how it goes.

en'til Zog · Post by **en'til Zog** » Thu Jun 14, 2012 12:58 am

YAYAY! Way to go Scott!

Good Luck skorpiyun!

florjon · Post by **florjon** » Thu Jun 14, 2012 3:28 am

I mix all my leds... White, red, blue..etc.
Then i have some general 5 volt resistor which i put on every led.
So each led a resistor. (example on photo)
http://i1224.photobucket.com/albums/ee3 ... 224042.jpg
I connect them all to some socket which is powered with a general 5 volt adapter. (like one from an old nokia phone or something simulair)

All still working

Mr. Engineer · Post by **Mr. Engineer** » Thu Jun 14, 2012 4:41 am

That's great. A bit nitpicking here but I prefer all exposed wires to be covered or have heat-shrink sleeves.

Kills the Murphy's Law gremlins when you seal up the model.

skorpiyun · Post by **skorpiyun** » Thu Jun 21, 2012 10:09 am

Hey guys. I got my Walwart, and a jack etc, and hooked everything up last night. It worked like an absolute charm!!!!!!!!!!

I had it on overnight, and everything is nice and bright, and no more Batteries!!! I really doubt i would have figured this out on my own, nor would I have had the guts to try it without the help from you guys. Huge thanx to everyone that chimed in with help/advice/input!!!!!! Really appreciate it!!!

I'll try to post a quick video of how she looks soon.

Thanx again,
D