9-volt wiring through cardboard house to light up

Who has had experience w/ using a 9-volt battery n' wires to light something up?

  • using wires and such

    Votes: 0 0.0%
  • and etc

    Votes: 0 0.0%

  • Total voters
    0
  • Poll closed .

Thread Starter

shadowed.angel

Joined May 8, 2008
5
If at all possible, can someone please explain how i would get this all work w/out a plug. But also explain to me if someone has ever done this. It would be a great deal of help, please and thank you.
 

Wendy

Joined Mar 24, 2008
21,848
I think you'll have to provide more information before getting a coherent answer. LED's come to mind, but I have no clue what your trying to accomplish.
 

beenthere

Joined Apr 20, 2004
15,808
Strongly agree. The question verges on incomprehensible. How could we possibly know if something we do not fully understand has been done before? What are we supposed to understand by "w/out a plug"?

Are you trying to place lighting (incandescent or LED) into a model house? If so, do all the illuminators come on at once, or do they need to be individually controlled?
 

Thread Starter

shadowed.angel

Joined May 8, 2008
5
The question in which you have replied with is the one that I was trying to ask. Having to deal with trying to illuminate up a model house with lights of any sort. In which this house is made of cardboard, being wired to a 9 volt battery. In which, my question is: has anyone try to do this sort of thing?
 

Wendy

Joined Mar 24, 2008
21,848
You ask a bunch of techie nerds if we've build doll houses? :) Nope, I never have. Just from an electronics point of view, use very lightweight insulated wire and solder it to the LEDs. Do you know how to solder? How much do you know about LED's and resistors?
 

Thread Starter

shadowed.angel

Joined May 8, 2008
5
I'm not talking about a doll house. This is a science project. And I have to admit; I know nothing about solder. If you could tell me what it is, it would be greatly appreciated. Thank you. And I'm not much of a science person, thats why I started this. Hoping to find out if anyone knows how to do this and etc.
 

Audioguru

Joined Dec 20, 2007
11,251
We know that a little 9V battery doesn't have enough power to light many lights for more than a few seconds.
We know how to design a simple circuit that has a big battery or a power supply and many lights with switches.
We know how to solder connections.
 

SgtWookie

Joined Jul 17, 2007
22,201
Basically, wiring up LED's (Light Emitting Diodes) is wiring up LED's, doesn't matter if it's a house or a printed wiring board.

A basic LED circuit consists of a current source (like a battery) a current limiter (such as a resistor) and the LED itself, with interconnecting conductors (wires, PWB traces, etc.)

You will probably want to use white LEDs. A 3mm or 5mm white LED usually has a Vf (forward voltage) somewhere in the range of 3.4v-3.9v with 20mA of current through it.

So then you need to calculate the value of Rlimit, the current limiting resistor. This depends upon three things:
1) The desired current through the LED
2) The Vf of the LED at that current
3) The supply voltage
Rlimit = (Vsupply - Vf(LED))/Desired Current
Rlimit = (9V - 3.6V) / 20mA (0.02A)
Rlimit = 5.4/0.02
Rlimit = 270 Ohms.
When the battery (alkaline) is fresh, you'll get 20mA of current through the resistor and LED.

A 9v alkaline battery is usually rated for somewhere around 500mAh. Many don't start out at 9v; more like 8.4v. But anyway, 500mAh means it can supply a current of 500mA for one hour, but more like 50mA for 10 hours. In your case, since you have a 20mA load, it will power your single LED for 500/20=25 hours.

If you add more lights, it will shorten your battery life somewhat porportionately.

But, batteries are much better at powering light loads than they are at powering heavy loads. If you have a lot of load on a battery, it starts heating up due to it's internal resistance. This heat is wasted power. If you had, say, 5 LEDs drawing a total of 100mA, your battery would likely last much less than 5 hours.
 
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Wendy

Joined Mar 24, 2008
21,848
If you have specific questions, like how to hook them up, you'll find a lot of help around here, but we can't help you if you stay vague on details. This is a science project, and you want to do what?
 

beenthere

Joined Apr 20, 2004
15,808
To get closer to the topic, I would never use a 9 volt battery if I wanted to have anything lit for more than 10 minutes. LED's or bulbs.
 
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