Thursday, March 12, 2009

Circuits


First, my apologies to readers who thought this was a
sewing blog. Er, you might be a bit disappointed today;
nay, horrified at what follows.

Next, a crafty-looking picture to soften the blow:
See granny reading her book and relaxing in her armchair?
See the table lamp lending light to her literary pursuits?
Today I thought we'd ... er.... make a small lamp.
With um... batteries and bulbs... and wires and.... stuff.

To defend myself a bit, I'm going to say I love my
sewing machine and my tubes of glue-with-intoxicating-
fumes. But I also love my multimeter and the tiny little
electronic components that are the innards of wonderful
things like flashlights and speakers. Combined with
cardboard, they make really silly and fun toys!

Still with me? OK, here goes.........

Now the circuit components can be bought in the form
of ready-assembled Science kits or individual pieces.
For retail stores, try places that sell homeschooling
resources, like ABCToy Zone (if you live in Singapore,
head to Sim Lim Tower and trawl the upper floors).
For online stores, try sites like this. Or you could
dismantle old gadgets that run on batteries
(stay away from TVs!) and save their innards like
my brother and I used to do as kids.

Here are some useful things to start with:


(Top row L-R: Insulated copper bell wire, alligator
(crocodile) clips, bulb holders
Bottom row L-R: bulb, switches, battery holders).

Or you could just get the barest and improvise with a
roll of masking tape, the way my brother and I did
all our experiments. The barest would be
  • A bulb - steal from flashlight
  • Wires - buy from hardware store and strip the ends with scissors
  • Batteries
and connect the parts of the circuit by just winding

and sticking down with tape:


If you can't find switches (which are nice for turning bulbs
on and off), make your own with cardboard and office
supplies. See here for the Switch Tutorial.


And if you can't find a bulb holder, use a wooden clothespeg
(the spring-loaded kind) or make a cardboard one.
Go here for the Bulb Holder tutorial.

But back to the lamp. These little bulbs are very safe
but tiny. To get some decent brightness, a reflector
is helpful. That's the silvery bowl that a flashlight bulb is
in the middle of. Make your own out of cardboard and
aluminum foil, if you like.
It's a bit like a cardboard collar for a dog.

Cut out a circle. Cut a quadrant out.
Also cut a small hole in the middle for the bulb.

Glue onto the dull surface of the foil
(we need the shiny surface exposed)

Cut around the cardboard,
leaving about a quarter inch allowance

to fold over the back.

Tape the straight ends together on the non-foil side

and stick a bulb through the middle hole.

To make the lampshade, I covered the outer
(non-foil) surface of the reflector with fancy paper.

The base of the lamp is a thread spool wrapped with
more fancy paper. The hole in the middle of the spool
is good for hiding wiring. Attach the shade to the base
with anything that props it up - a roll of stiff
transparent plastic (poke holes for ventilation)
or toothpicks glued down.

For the circuit you'll need
  • 1 or 2 batteries (any size except the square 9V). 2 batteries give a brighter light.
  • 3 insulated wires with stripped ends
  • A switch
I taped two AA batteries end-to-end with the
"-" of one touching the "+" of the other.

Following the circuit diagram,
  • Wire 1 joined one end of the battery pack to one paper fastener of the switch.
  • Wire 2 joined other paper fastener of the switch to the bottom of the bulb.
  • Wire 3 joined the metal casing of the bulb to the other end of the battery pack.
All the "joints" were secured with masking tape -
just to reassure everyone that the official fancy
components aren't really needed to make this.


Install lamp in resident dollhouse and enjoy!

Bet you all didn't see that coming.
Loopy blog author!


10 comments:

  1. Just when I thought you couldn't possibly be any more fantastic, you go and pull a stunt like this. So so wonderful!

    And gets me all eager to start working on my dollhouse again for the girls (the one I played with in Singapore when I was their age!) But first will work on finishing all these other various projects o' mine...

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  2. Your pictures remind me of the ones Jeff has been taking for the Physics textbook he's been writing. He'd love them!

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  3. Oh! Memories of primary school came flooding back...

    Circuit boards....I always preferred to draw mine rather than make a working sample (because they almost always failed) :(

    Love the whole playhouse thingy. Where did you get them wooden sofas?

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  4. 1. Not unexpected. You are Physics teacher before right?

    2. Your handwriting has not changed!

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  5. Is there anything you don't do? Please let me know so I can feel better about myself :-)

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  6. You are so amazing, I am so blown away by your creativity and ingeniuty!!!

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  7. Love this! Thank you, thank you! This is so helpful with my 4th grader's homework project to build a model of a simple circuit in a shoebox. But I'm puzzled as how you attached the wires to the bulb in the lamp shade without them bulging out. Any advice?

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    Replies
    1. Jenn: stuffed them into the bore of the spool.

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  8. Thank you ! I've been wanting to try this for years, but hadn't found a tutorial that madesense to me (until today).

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