Fun with Less Kilowatts: Valentine Operation

By Vernon Trollinger, February 13, 2017, Family

Welcome to Fun with Less Kilowatts! We believe that science experiments at home can be a creative way to engage kids in learning while having fun. They can be educational AND great activities to keep your kids busy and away from the television. Each month, we’ll feature a new science experiment that can be a great resource for parents and teachers.

Valentine Hearts Operation

An Instructables writer named mathiemom posted a fun variation on the classic kid’s game, Operation, that uses a box of the equally classic Sweethearts Valentine candies. The candies — which have been around since 1866 — are the ones with little messages printed on them like, “Let’s Kiss”, “I Dig You”, and “Love”. Since the circuit is very simple to build with a few odds and ends, you and your kids can make a fun game to play with this or other Valentine candy while learning how an electrical circuit works.


The Materials

  • One 0.9 oz box of Sweethearts Candies.
  • A 9 volt battery.
  • A string of old Christmas lights (non LED)*. You’ll need to cut off a two-bulb segment. You can also use a 5 volt piezo buzzer.
  • Metal tweezers
  • Scissors
  • A foot of light gauge stranded wire OR a test lead with alligator clips.
  • Tape or electrical tape.
  • Aluminum duct tape. They are sold in home centers and used to seal duct work joints. Very strong with a good adhesive, you can use this for a lot of repairs. It runs about $8 to $10.

In this version, I’m trying to simplify mathiemom’s construction. The main difference is I’ve decided to make the box’s contact out of aluminum duct tape instead of the bent paper clip and brass fasteners. This way, the metal tape acts as both the contact and fastener and won’t jiggle loose at the critical moment.

*NOTE—You could use an old string of LED lights, however, you’ll want to use a lower voltage power source such as an AA battery holder like the kind for LED flashlights. You’ll need fewer LEDs with the lower voltage.

The Directions


1) Cut out a heart-shaped hole in the front of the box.

2) Cut a piece of the aluminum duct tape just big enough to be the same width as the box’s front panel. Remove the backing from the tape. Slide the tape into the box so that you can see the dull-colored adhesive or sticky side of the tape through the heart.The shiny side should be facing the inside of the box. Push the tape so that it sticks to the inside of the front panel.

3) The dull, sticky back of the tape will be visible where you cut the heart-shaped hole in the box. Cut an X into this to make flaps and peel them back to the edge of the hole. Press them in place. Do not tear them off or remove them. You want the metal tape to line the edge of the hole.

4) Cut the end off a piece of the stranded wire, strip half an inch of insulation off and spread out the strands into a fan shape.

5) Take a piece of regular tape and tape the wire fan to the shiny side of the aluminum tape inside the box. Keep it away from the edge of the hole. The shiny side of the aluminum tape will conduct electricity. The sticky side of the aluminum tape won’t do as good a job because it’s covered with adhesive.


6) Strip the other end of this wire and attach it to one of the 9 volt battery terminals. You keep it in place by wrapping some tape over the wire and terminal.

7) Take your old Christmas light strings and cut off a length of two or three lights that are connected to each other. Strip the insulation from the wire ends. Twist the bare wires ends so that each end isn’t frayed.

8) Connect one of these wire ends to the alligator clip lead. Clip the other end of this alligator lead to one of the 9 volt battery terminals.

9) Add a face and some decorations to the box. To keep this simple so you can see everything, I just made a face using the heart cut out of the box panel and used that as a place to mount one of the lights.

10) Put the candy into the box and take turns taking out pieces with the tweezers without turning on the lights.

The Result


As long as the metal tweezers don’t touch the edge of the hole or the aluminum tape, the lights will stay dark. But even if the tweezer just brushes the metallic tape, the lights will flash on.

The Science

Batteries have two pole or terminals; a positive and a negative. Inside the battery, the poles are separated by a membrane. When there’s a complete circuit, a chemical reaction occurs. Electrons on the positive side flow through the membrane into the negative side. To complete the reaction, the electrons must return to the positive side. But because the membrane only works one way, the electrons cluster around the negative terminal and leave the battery to find a way back to the positive terminal to complete the chemical reaction. In the case of an alkaline battery, zinc and manganese oxide are consumed during the reaction.

Meanwhile, as these electrons are on their little trip down the wire heading back home, we can put them to work lighting up light bulbs or making buzzers buzz or powering portable radios or lots of other useful stuff.

As mentioned, the chemical reaction in the battery only happens when electrons can move out of the negative terminal of the battery and head down the wire to the positive terminal in a completed circuit. During the game, the circuit is only completed if the tweezer touches the aluminum tape. The lights turning on show that electrons are moving through the completed circuit and the chemical reaction in the battery is underway!

Do you have any fun and kid-friendly science experiments you’d like to see us try for Fun with Less Kilowatts? Share with us in the comments!

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A native of Wyomissing Hills, PA, Vernon Trollinger studied writing and film at the University of Iowa, later earning his MA in writing there as well. Following a decade of digging in CRM archaeology, he now writes about green energy technology, home energy efficiency, DIY projects, the natural gas industry, and the electrical grid.

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