Introduction: Flux Capacitor (omaha Maker Group)

Picture of Flux Capacitor (omaha Maker Group)

1.21 Gigawatts?   Try 9 volts of pure direct current.   It won't transport you through time, but then it isn't exactly going 88mph yet.
This was an experiment I did with Bare Paint (conductive paint) in order to see if I could make the ever famous movie prop, the Flux Capacitor. This was done for the Omaha Maker Group and our May 21 build night with the focus on Bare Conductive Paint.   In honor of Marty McFly, my flux capacitor is chicken yellow.

Parts List:

3 4401 NPN transistors

3 capacitors 4.7uf

3   47 k resistors   yellow purple orange gold

2   470 ohm resistor   yellow purple brown gold

1  120 ohm resistor  brown red brown gold

1  100 ohm resistor  brown black brown gold

9 volt battery

1 tube of Bare conductive paint

Step 1: Step 1, Printing the Flux

Picture of Step 1,  Printing the Flux

Print out the page attached.  Glue to cardboard backing, and trim to size.  Use a push pin to create holes at the black dots, then mount the LED's through the holes.   Be sure that the negative side of the LED (Flat part) is facing to the left.  Using a needle nose pliers to crimp the LED wires into the cardboard.    Tucking these in will give you the ability to use the Conductive paint to try and complete pathways.  (Hint: Shorter pathways stand a better chance of working).    Also it will make it easier should you decide to solder these with connecting wire later on.

Step 2: Step 2, Building the Circuit

Picture of Step 2, Building the Circuit

Study the supplied schematic.   You will be running 3 sets of LED's groups of 3 each in parallel, within the series pathway.  The finished circuit will blink from Left to Right following the schematic.   Using a perf board from Radio shack, mount the NPN Transistors.   You may wish to do a test on a breadboard, like I did, to verify that you have realized the circuit correctly.

After all 3 leads of each transistor is set in a copper pathway of its own, add the 3 connecting wires to ground from the left side of each (the flat side facing you).    Add next the capacitors to the right lead on the Transistor (Right of the flat side).  Pay close attention that the side of the capacitor with the arrows down terminates at the negative, or cathode.

Use the claw-like wire cutters to remove extra lengths of wire after they have been soldered.  Wire together the 100 and 150 ohm resistors to bring down the supply voltage from the 9V battery, thus avoiding burning out the LED's.   Add the remaining resistors to the circuit and connecting wire.

Step 3: Step 3, Connecting the Circuit to the LED's

Picture of Step 3, Connecting the Circuit to the LED's

Connect the red lead of the Battery adaptor to the 2 resistors wired in series.   Solder them together, then solder to the first of the bottom row of LED's.   Next,  solder connecting wire to the other two LED's on their positive side.  Solder longer connecting wires to the perf board to connect to the negative side of the first 3 LED's on the bottom.  Here is a good place to pause, and test with the 9V to make certain the circuit is working.  

Once I verified the lights blinked in sequence, I added Bare Conductive paint to each of the corresponding negative and positive terminals on the LED's.   After it dried, the lights blinked poorly or not at all.   This was due to my design error, as I didn't take into consideration the amount of resistance of the conductive paint.   Oh well, it still looks cool and very "Spidery!"

I decided to perform a bypass of this circuit trace and add in red copper connecting wires to all the LED's and it now works.   I hope you enjoyed learning how to create a Flux Capacitor on the cheap!   Woo Hoo!

Step 4: Enjoy!

Plug in your 9V battery and enjoy the device.  You may now hang it up in your Delorean.


Insonicbloom (author)2015-10-18

I did a similar version of this a few years back but on stripboard

technovative (author)2013-06-13

Nobody calls me chicken! Great Scott this is a cool project, I love transistor circuits, & BTTF.