Introduction: The Enigma Puzzle Box

Picture of The Enigma Puzzle Box
<-----UPDATED 2/3/12----->

I now have added a locking device in the form of a solenoid. When the amber LED lights up, the solenoid pulls in its plunger from the "lock" (a piece of MDF with a hole in it) and the box opens. I have updated the images to show this change.

So first off I apologize for not making a formal instructable. When I started this project all I wanted to do was jump right in and get it done. If you have any questions regarding the box's construction, coin slot construction, or circuit design, please leave a comment and I'll try to assist you as much as possible. Also keep in mind the construction of the coin slot is not necessary, you can remove it if you don't want to make it. Also I suggest you make the box, drill the holes, stain (not really needed, but its a nice touch), then solder in the electronics. Trust me, it will take longer but its worth it. Speaking of taking a long time, don not rush this project, take your time.

Materials Needed:
- 1 Rotary Switch.
- 16 SPST Toggle Switches.
- 1 Power Switch (also SPDT, but anything works).
- 1 Green LED 1.5vDC preferred.
- 6 VDC Solenoid.
- 1 Resistor 100 ohms +/-5% (Black, Brown, Black, Gold)*
    *The resistor was 15 ohms, but I changed it so now the LED's won't burn out. 
- 1 Amber (yellow) LED 1.5vDC preferred.
- 1 Battery Pack for 4 AA Batteries.
- 1 Box

- Plexiglass or other material to make coin slot.
- Stain
- MDF 1/8 for lock latch.

The "codes" are as follows (refer to circuit diagram):

Puzzle Setting 1 (Yellow Line): B1, D2, A3, A4.
Puzzle Setting 2 (Blue Line): A1, B2, D3, D4.
Puzzle Setting 3 (Orange Line): D1, C2, C3, B4.
Puzzle Setting 4 (Green Line): C1, A2, B3, C4.

Once all the correct switches have been flipped, the amber (yellow) LED will turn on.

Thanks for taking the time to read this instructable, all the best in future projects!


cdh89 (author)2017-01-17

Would you be willing to make one for me? If so what's your cost?

garrenmelton (author)2012-05-12

Would turning on all of the switches just open the box? If so how could I prevent that?

LaurenLaLa (author)garrenmelton2016-11-11

Just install two of the stiches upside down on the box. That way when they are all switched "on", those two switches would actually look switched on, but they would be switched off.

TXTCLA55 (author)garrenmelton2012-05-12

Well I used the coin slot as a means of needing a certain coin to turn on the power.However I discovered that this can be by-passed quite easily. Your next best option would to use a key switch. Unfortunately, the only real way to ensure a secure locking box would be with a micro controller. Hope this helped.

JoshG65 (author)2016-03-04

Can someone offer me some assistance on the wiring of this box? I am having a little trouble. Please email me @ and I can send pics of what I've got and what it is or isn't doing. Maybe I'm just having trouble with the wiring diagram but it is frustrating me. :(

JoshG37 (author)2015-11-26

What are the specs for the rotary switch. they are all so confusing. how many pole, how many positions, how many pins?

SpencerJ2 made it! (author)2015-10-10

fun box but you have two different pictures some with the silonied some without

MelanieC8 (author)2015-09-14

i can't see the first video! :/

lagartonverde (author)2015-05-13

Where can i buy it!!! please!

Doctor-X17 (author)2014-09-01

Looks nice. Maybe not a real security solution, but it's certainly a cool gift or conversation starter.

dmers97 (author)2014-06-08

how does the key slot work? does it hit a switchor just electrically connect everything?

merlin867 (author)2014-04-23

I will try soon. But onw question is on my mind. What kind of solenoid did you use? Push, Pull, both? How did you get it lock after powering off?

Sorry for my english, i'm french!

nate408 (author)2014-03-13

that is so cool! I may try to make one.

djsfantasi (author)2013-12-19

Another idea is to use SPDT switches instead. Then for each possibility, some switches need to be down and others up to open the box.

NeverBoringNeverBored (author)2013-10-13

Thanks for a great idea! I'll be using mine to hide my boys Christmas gifts!

kchao35 (author)2013-09-26

How much energy/voltage is needed to run this box? Considering using a solar panel instead of batteries.

TXTCLA55 (author)kchao352013-09-28

It really depends on what voltage the solenoid is. 6V is the standard from what I saw, not sure if you can find something lower than that. A better option would be to find a (or some) solar panels that can put out 9V.

dirtbikedude199 (author)2013-01-30

how much would it be for you to make me one and I buy it from you?

RolfFishMan (author)2013-01-24

If I would switch every one of them, wouldn't the box just open?

sony52 (author)2012-10-25

Where did rotary switch from?

sony52 (author)sony522012-10-25

Also would this be a good substitute?

TXTCLA55 (author)sony522012-10-25

I would think so. I used a 12 pole because I bought mine from a local supplier. Really any model should work.

sony52 (author)TXTCLA552012-10-29


Think with portals (author)2012-03-14

where did you find the key slot?

My brain. I made it by measuring the diameter of a quarter. Then I measured the thickness of two quarters. After that, it was a simple of matter making the slot out of plastic, then cutting a slot in the side for the switch.

DT sleper (author)2012-01-30

Blue Line Uses B2 also per your schematic.

TXTCLA55 (author)DT sleper2012-01-30

I am not sure what you mean, if you mean the blue line shares a connection at the end of its line you are correct and it should be this way.

DT sleper (author)TXTCLA552012-01-30

On puzzle setting 2 you show it only uses A1,D3, and D4 but on your circuit diagram B2 must also be in the closed position.

TXTCLA55 (author)DT sleper2012-01-30

Ah your right, but for some reason when I use that combination A1, B2, D3, D4 the box doesn't open. However when I put B2 into the off position it opens...Its strange, if you bold the circuit your self you may encounter the same result.

DT sleper (author)TXTCLA552012-01-31

I looked at your picture showing the connections (crazy mess of wire) and it looks like b2 is mounted backwards so that when it is in the "off" position with the rest of the switches it is really "on". That would make the puzzle more difficult I think , if you randomly mounted the switches so that you would not know which way is on or off.

TXTCLA55 (author)DT sleper2012-01-31

Yeah I thought about doing that, but when it came time to solder all them, it proved a bit to complicated for me. I am sure that if your able to do it, you should because it would make the box harder to open.

rickharris (author)2012-01-31

LED's RESISTORS - Steve did tell you!

TXTCLA55 (author)rickharris2012-01-31

I know, in the future I'll add it in. I have yet to buy the parts needed to upgrade the box.

iceng (author)2012-01-30

You might make each switch in a row when turned on disable the
other switches in the row.  Otherwise turning all on unlocks all.


TXTCLA55 (author)iceng2012-01-30

Thats kinda what the key slot is for.

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