Need advice regarding a major voltage drop.

Ask and answer questions, share tips and resources for installing lighting and other electronics in your models.

Moderators: Sparky, Moderators

Post Reply
User avatar
MillenniumFalsehood
Posts: 17033
Joined: Tue Nov 16, 2004 5:23 pm
Location: Wichita, KS, USA
Contact:

Need advice regarding a major voltage drop.

Post by MillenniumFalsehood »

I'm attempting to hook up a simple blinking circuit parallel with a string of white LEDs in a ship I'm modeling. The problem is that the blinker draws a lot of current, so much so that it significantly dims the whites on the other circuit. My question is, what would be the best solution for this? I'm thinking a voltage regulator, but I don't know much about them.

Stats:

3mm White LEDs x13 in parallel

5mm Green, Red, and Blinking Red LEDs

1mm Red LED x4 wired in parallel to a solid-state blinker.

Each one is a circuit which runs on 3 volts.
If a redhead works at a bakery, does that make him a gingerbread man?

Ponies defeat a Star Trek villain? Give them a Star Wars award ceremony!
User avatar
Mr. Engineer
Posts: 440
Joined: Mon Dec 10, 2007 6:01 am
Location: Malaysia
Contact:

Post by Mr. Engineer »

For all LEDs, did you use any current limiting resistors on them?
What can I take apart today?

https://www.facebook.com/PisceanWorks
User avatar
MillenniumFalsehood
Posts: 17033
Joined: Tue Nov 16, 2004 5:23 pm
Location: Wichita, KS, USA
Contact:

Post by MillenniumFalsehood »

Yes, one per string(they're all in parallel). The ratings are:

150 ohm on the red-green-blinking red and the 1mmx4 strings.

51 ohm on the white LEDs.
If a redhead works at a bakery, does that make him a gingerbread man?

Ponies defeat a Star Trek villain? Give them a Star Wars award ceremony!
User avatar
brt
Posts: 1932
Joined: Thu Feb 14, 2008 6:04 pm
Location: Waiting for the Mothership

Post by brt »

Frequently 3mm and 5mm LEDs require 3.4 to 3.6 volts. 3 AAs would be needed and then the appropriate resistors. If your blinker is a 555 timer you lose 1.7 to 2.0 volts across it, so you would then need 4 AAs.
User avatar
tetsujin
Posts: 2353
Joined: Mon Feb 28, 2005 6:08 pm
Contact:

Re: Need advice regarding a major voltage drop.

Post by tetsujin »

MillenniumFalsehood wrote: 1mm Red LED x4 wired in parallel to a solid-state blinker.
I'm confused... Why would the LEDs be wired in parallel to a blinker circuit? That sounds kind of messed up. Can you give me a schematic or something?
---GEC (三面図流の初段)
There are no rats.
The skulls eat them.
RossW
Posts: 198
Joined: Wed Oct 02, 2002 1:04 pm
Location: Toronto, ON

Post by RossW »

I think he means the blinking circuit is wired up in parallel with other, non-blinking LEDs.

Yes, you need a voltage regulator. Batteries won't do it. You can build your own, but a wall wart which is specifically tagged as regulated voltage is your best bet.
Post Reply