Introduction: Piezo Pen Pulsed Power Source

About: I've built some weird stuff over the years, but most of that stuff has remained unseen by the world outside of me and a few friends. But then one day, one of these friends, he says to me, "Hey Jack, you shoul…

In this instructable, I pull the piezo sparker module out of a barbecue lighter, and transplant it into the body of what used to be a clicky-type retractable ballpoint pen.

Providing pulsed power when you press the plunger,  this pocket-sized plaything is sure to be a pleasing plus to the plurality of pens and pencils presently populating your pocket protector.


In other words it's a little toy that looks like a ballpoint pen, but shoots tiny lightning bolts out of its tip. This toy can be used anywhere where a short duration multi-kilovolt pulse is required.  It can be used for making tiny lightning bolts,  briefly illuminating certain gas filled tubes, triggering a camera flash, starting stubborn fluorescent lights,  and certainly other applications as well.

You can also use it to light your stove or gas grill.

The basic trick is just pulling a piezo module out of lighter, and then transplanting it into a ballpoint pen body.

Beyond that basic idea, this instructable goes into excessive and excruciating detail, as to one particular way to do this. 

One of my goals was to make it look nice.  Another goal was to make the finished product look as much like a stock ballpoint pen as possible. 

If you dispense with those goals (pretty, and pen-shaped), you can probably cobble together something that  works, i.e. something that will make an electric pulse, when you push down on the little spring-loaded hammer.  For example the barbecue lighter I use comes in a nice red, plastic case, with a trigger and everything.  So if you just run the wires outside the case to where you want them, that just might be what you want...

However,  it would not resemble a ballpoint pen. And that's what I want, is something that looks like a pen. That's what  my internal voice of ineffable desire says that it wants.  The voices say making it look like a pen would be sexy.

Electrically the Piezo Pen is a two terminal device. One of those terminals is the plunger at the top of the pen, which is connected to the user's thumb.  The other terminal is writing tip/stylus, at the bottom of the pen. When activated, i.e when the spring-loaded hammer hits the magic crystal,  a high voltage pulse appears across these two terminals.

Note:  the user of this Piezo Pen is necessarily part of the circuit, and he or she is connected to the Piezo Pen via his or her thumb on the plunger.Usually the object being zapped, e.g. fluorescent tube, gas stove, etc., is held in the user's other hand, and the path for the electric current is through his or her body

Or through its body, in the case of a non-gendered robot using the Piezo Pen.

The reason I put those words in bold  is because depending on what you're sensitive to, electric shocks, even mild ones, might be harmful.  This is especially true if you're a robot, or if you are a human with implanted electronic devices, e.g. a pacemaker, or an insulin pump, or a I-know-not-what. 

I just wanted to mention the Piezo Pen described in this instructable does connect electrically to the body of the user, and if that's going to be problematic for you, then you shouldn't play with it.  Sorry.

Step 1: Prior Art - Grill Lighters and Qi Stimulators

In the prior art, these little piezo thumper modules are used to provide a small electric spark for the purposes of igniting a gas-air flame, as in a barbecue lighter, or candle lighter, or even in some small cigarette lighters, and/or small butane powered torches.

That's what they're usually used for.

Also worth mentioning are some gizmos sold under the aegis of alternative medicine. Words typically found in advertisement/documentation for these devices include:   acupuncture, acupressure, stimulation, qi?

Some links:

I dunno, I guess shocking yourself with a piezo module can be theraputic. Erm... Maybe... If you do it right.... Actually I'm not qualified to say what the health effects are, if any, and whether or not it's good for you.

However, if you want to give it a try, and you want a cheaper alternative to their magic stimulator wand, sold for  30 USD, or 60 USD  (priced at the time of this writing) , I think the Piezo Pen described in this 'ible gives you basically the same thing.  Like the gizmos sold at  the links above, my Piezo Pen has one of its terminals on the top, where the thumb pushes the plunger, and the other terminal at the bottom.  And I am guessing it works the same way.

I am sure if you actually asked any of the sellers of the above linked piezo "stimulation" devices, that they'd assure you their device is superior to anything you or I could build at home from a hacked butane lighter.  I mean it would kind of have to be better in some way, in order to justify the price they're asking for it. Right?

Step 2: Materials and Tools

To build my Piezo Pen I used the following materials:
  • 1 Refillable Muli-Purpose Lighter (aka Butane Barbecue Lighter)   (UPC 7-14638-02020-9)
  • 1 Inc(r) brand Classic Gels(r) Retractable Gel Roller Pen (comes in pack of 2) (UPC 7-24328-86012-1)
  • 1 Papermate(r) Eagle(r) Capped Ball Point Pen (comes in pack of 10) (UPC 0-41540-00428-8)
  • solid copper wire, 24 AWG (same gauge as found in CAT5 cable)
  • brass rod, 1/4 inch diameter (length 1+1/4 inches needed)
  • solder 40/60 Pb/Sn, rosin core
  • 1 wooden toothpick, round
These materials are shown in the first pic.  The second pic shows some of the back matter, UPC numbers, company names and addresses, and warnings and stuff, and at least one old US Patent number.

I also used the following tools: 

Third pic shows safety glasses, ruler, pencil, razor blade, wire cutters, tubing cutter, solder, helping hands, soldering gun, small butane torch.

Forth pic shows my small drill press, plus some tools for grinding and smoothing: file, sandpaper, and steel wool.  Also a push-pin for making "starter" holes.

Fifth pic shows my vise and my hack saw.

Step 3: Check to Make Sure It Will Fit

One of the most challenging parts of this ible was finding a ballpoint pen with an inside diameter large enough to accommodate my piezo module.

The pen I found for this task, the Inc(r) brand Classic Gel,  is very roomy on its cylindrical inside, with an inside diameter of about 9.4 mm.  Most ballpoint pens I found were much smaller than this.

I tried to be specific in the previous Step,  providing exact description of the parts, i.e. materials,  I used at the time and place of this writing,  but I can only guess what size of size pens and piezo modules you'll be facing at your local marketplace.

Anyway, getting the module to fit inside the pen is kind of important, and it deserves its own Step. Pictures of me demonstrating the module actually fits inside the pen body, are attached here to this Step.

Step 4: Take Apart the Lighter

I take apart the barbecue lighter.  It is held together by two screws, and a little plastic ring that slips over the metal tube part that the flame comes out of.  My goal here is to retrieve the magic piezo sparker module.  A close-up picture of this is shown in the last photo for this step.

For those of you who are curious as to how the piezo module was wired into this barbecue lighter in the first place, you can sort of see this in the second picture.  The only thing not shown is the spark gap, at the end of the metal tube, in the place where butane meets air.

I'm sure there is something interesting that can be done with these extra parts:  the plastic case, the little butane reservoir, plus valve, plus the long plastic tubing, etc.  Although, at the moment, I'm not sure what that something is, so all the extra parts go into the "junk box".

Step 5: Drill a Small Hole in the Top of the Piezo Module

Using a push-pin, I make a tiny pin-sized hole in the center of the top of the plunger of the piezo module. This is shown in the first picture.

Next I hold that starter hole against a spinning 1/16-inch twist drill bit, which is held by my little drill press.  The plastic is soft, and a careful upward force, pushing the piezo module up into the drill bit, is all that is needed to punch a small hole here.

The reason why I'm punching a hole in the top of the piezo module is because this provides a way to connect electrically, the brass plunger at the top of the pen, to the little metal parts inside the piezo module. 

It just so happens that these internal metal parts are connected to the place I want to connect to, and drilling a hole here is a convenient way to make that connection.

When it fires, a high voltage pulse appears, between the internal metal parts (including the spring inside the plunger in the top of the piezo module) and the little yellow wire that comes out the side of the module.  That is to say there are two terminals.  One is connected t those internal metal parts, and also the big metal cylinder on the bottom of the module.  The other is connected to that yellow wire coming out the side.

More details on the brass plunger-terminal, and how it gets connected to the top of the piezo module, are mentioned in  Steps 11 and 16 respectively.

Step 6: Take Apart Both Pens

The Inc(r) Classic Gel(r) unscrews, and the pieces pretty much just fall out.  This is shown in the first picture.

The Papermate(r) Eagle is disassembled by pulling it apart.  Its pieces are shown in the second picture.  Getting the end plug out is kind of tricky.  I drive it from the inside by pushing a steel rod through the body of the pen, shown in pic 3.

The forth picture shows a close-up of the brass tip from the Papermate(r) Eagle(r).

There is a trick to removing the ink from the ink tube.  I do this by using a piece of wire to push a wad of paper-towel through the tube and squeegie out the ink.  I don't show to do that here, but I do show how to do this in Step 9 of this other instructable involving ballpoint pen parts.

The parts I want to try not to lose,  because they will be needed in subsequent steps, include:  most of the parts from Inc(r) Classic,  except for the ink cartridge,  and from the Papermate(r) Eagle(r):  the body tube, the ink tube (emptied of its ink), and the tiny brass tip 

Step 7: The Proper Way to Cut Plastic Pen Tubing

The Papermate(r) Eagle(r) pen provides two pieces of plastic tubing, which are cut to length in this step.  I want a length of pen-body (8mm OD) tubing, 1+1/4 inches long, and I want a piece of ink-tube (3mm OD) tubing, 3+1/4 long.

The best way I have found to cut sections of plastic pen tubing, so that I get a nice square cut, is to (1) mark the place where I want the cut, (2) score this mark using a tubing cutter, like the kind used for cutting copper tubing for plumbing.  The tubing cutter scores a perfect circle where I want the cut to go, but will not succeed in actually cutting plastic tube, which is why it is necessary to (3) remove the tubing from the tubing cutter, and (4) go over the scored circle with a sharp razor blade, sort of "rolling" the pen underneath the blade.    This method is shown in pictures 1-3, and the resulting pretty cut ends are shown in picture 4.

The ink tube is too small (3mm outside diameter) to fit in tubing cutter.  So I do the best I can to make this cut square, using just the razor blade alone, in picture 5.

Step 8: Drill Holes in Tubing Sections

I want to put some holes in these two pieces of tubing.  In both cases, the reason for this is because there is a wire I want to route from inside to outside.  The wire is shown in subsequent steps.

For now the game is to put a small hole in the tube with a push pin, and then drill that starter hole using the drill press.

The locations where I want the centers of these holes:

For the ink tube: 1+1/4 inches from one end.

For the body tube: at its midpoint, or equivalently 5/8 inches from either end.

For both the size of the hole is 1/16 inch in diameter.

This is all shown in the attached pictures.

Step 9: Brass Tip/bottom Terminal

This step shows how to make the tip terminal.  This part will go into the bottom of the pen.

The brass tip itself is the tip removed from the Papermate(r) Eagle(r) in Step 6.  As found,  it is not exactly the shape I want it to be.  It is shaped like an arrowhead, and it just a little too wide to fit through the hole in the end of the Inc(r) Classic Gel (r) body.  So I chuck this brass tip into my drill press, and grind it down a little bit, so that its shape resembles  a "bullet" more so than an "arrowhead".  This is shown in pics 1-3.

Next I solder a piece of solid 24 AWG copper wire into the end of this brass tip, and I thread the wire through that piece of ink-tube, and stuff the tip into the end of the piece of ink tube.  Last, I bend the wire over, and trim it off.  This is shown in pics 4-7.

Step 10: Bottom Assembly

I take the wire lead, coming out of the side of the piezo module, and I thread it through that section of pen body tube with hole drilled in the center (in Step 8). 

Then I attach the end of this wire to the spring, from the clicky-retractable mechanism, of the Inc(r) Classic Gel. 

I don't solder this connection.  The wire is held in place in the one of the ends of the spring, where the springwire is coiled tightly. See picture 1.

Next, in picture 2,  I slide the tip/bottom terminal and its ink-tube section through the spring, and through the section of pen-body tube.

Next I take it all apart, because I take it all apart, because I decided the length of the ink-tube section wasn't quite right.  It looks like I decided on a length of 3+5/16 inch for the total length of ink-tube and brass tip together. See picture 2. 

Next I put it all back together again, and the completed bottom assembly is shown in picture 4.

Step 11: Brass Plunger/ Top Terminal

The brass plunger, which is also the electrical terminal at the top of the pen,  is made from a piece of 1/4 inch diameter brass rod stock, with a length of 1+1/4 inches. 

On the end that goes inside the pen, this brass plunger is grafted to a piece of the original plastic plunger.  I made the decision to marry these two pieces of plunger together for two reasons.  One is that the little groves that are part of the original plunger mechanism, help it slide in and out smoothly.  The second reason is that this shape keeps the plunger from falling out the top of the pen.

Also on the end of the plunger that goes inside the pen, a small piece of solid 24 AWG copper wire is soldered to the brass plunger, and it is this little stubby piece of wire that connects the plunger electrically to the piezo module, through the hole I drilled in the top of the piezo module in Step 5.

The only picture attached to this step is a picture of what the finished brass plunger looks like, complete with plastic end attached, and copper wire soldered to the bottom. The next three steps, after this one, show the excruciating details of me making this brass plunger piece.

Step 12: Brass Plunger - Cutting and Grinding

The pictures attached to this step show me cutting off a length of brass rod (1), cutting off the part of the plastic plunger that I want to keep (2,3),  shaping and smoothing the part of the brass plunger that goes outside the pen (4, 5, 6), and reducing the diameter of the plunger, on the side that goes inside the pen, until it will fit inside that little piece from the plastic plunger (7,8).

Step 13: Brass Plunger - Soldering

In this Step, I solder a little piece of solid 24 AWG copper wire onto the end of the brass plunger.  It is by way of this little wire, that the plunger will connect electrically to the piezo module.

This is kind of a big chunk of brass, and it takes a lot of heat to make it hot.  So I use my little pocket butane torch, instead of the soldering gun.

After finishing the soldering, I think it took about a minute or two before this thing was cool enough to handle.

Step 14: Brass Plunger - Plastic End Piece

The plunger connects mechanically to the piezo module, by, you guessed it, by pressing on top of it.  It is by way of the plunger that the force from my thumb compresses plunger on the piezo module.

On the end that goes inside the pen, this brass plunger is grafted to a piece of the original plastic plunger. I made the decision to marry these two pieces of plunger together for two reasons. One is that the little groves that are part of the original plunger mechanism, help it slide in and out smoothly. The second reason is that this shape keeps the plunger from falling out the top of the pen.  These plastic and brass pieces are held together by a tiny wooden pin that used to be part of a toothpick.

Step 15: Top Assembly

The top assembly is just the brass plunger, plus the top piece from the Inc(r) Classic Gel(r) body.

Step 16: Bottom and Top Come Together

Finally, the pieces of this pen are about to come together.  The first picture shows the top and bottom assemblies.  Although for some reason, the bottom assembly is shown in the top part of the picture, and the top assembly in the bottom of the picture.  But no worries!

The second picture shows me screwing together the top and the bottom assembly.  While doing this, I make sure the little wire on the bottom of the brass plunger lines up with, and goes into, the hole I drilled in the top of the piezo module.

The third picture shows the completed Piezo Pen, side-by-side, with the original stock Inc(r) Classic Gel(r) ballpoint pen, and they look similar.  That was one of my goals:  to make this thing actually look like a stock ball point pen.

The last picture in the stack shows me taking this thing for a test-spark!  Ker-zap!!!

Step 17: Zapping Gas Tubes: Neon Lamp

The electric pulse produced by the Piezo Pen can briefly illuminate various gas filled tubes.  The pictures for this step show me zapping a neon indicator lamp. The gas inside the little neon lamp glows orange when it is excited.

Step 18: Zapping Gas Tubes: Xenon Flash Lamp

The electric pulse produced by the Piezo Pen can briefly illuminate various gas filled tubes.  The pictures for this step show me zapping a xenon strobe tube, like those found in a camera flash. When this gas tube gets pulsed it looks like there are tiny lightning bolts inside the tube.

Step 19: Zapping Gas Tubes: Compact Fluorescent Bulb

The electric pulse produced by the Piezo Pen can briefly illuminate various gas filled tubes.  The pictures for this step show me zapping a CFL, aka a compact fluorescent light bulb.  As can be seen from the pictures, I am zapping it through the glass. That is:  my left hand holds the CFL by its twisty glass tube, and my right hand works the brass plunger.  As is the usual trick for using this Piezo Pen, my body completes the circuit for the current pulse.

Glass is a good electrical insulator, so you might be asking yourself why this trick works at all.  How can a current pulse travel through a layer of glass?