Author Topic: DIY: How to make tip pressure IR pen (Read 24972 times)

Marttyn · **on:** August 12, 2008, 10:20:23 AM

Hi!
Ive joined this community a couple of weeks ago. A few days ago ive constructed my own design of pressure pen and works GREAT. I see that not many people have one of this, and the ones that have one, are quite complex to build.
My design is VERY simple and i want to share it with every one.

BUT FIRST! I want to warn this kind of pen is not suitable for everyone. Because the leds is touching and slideing through your whiteboard the surface must be VERY smooth, otherwise the feeling would not be pleasent, and the led will get scratched. If you are writing on a wall or blackboard there are other suitable pens for you

You need:
1x Pilot Super Color Marker
1x IR LED (Vishay TSAL6400 or TSAL5300 for best performance)
1x Momentary switch button
2x AAA batteries
1x 12ohm resistor 1/4 watt

For the conections, instead of normal wire, i use insulated copper wire 0.2mm diameter (about 32Gauge)

The circuit cant be more simple:

Now, to assamble the pen:
First unscrew the tip of the marker and take out the cotton filling with the ink. You should keep only the tip, the tube and the cap.
Pour some alcohol inside the tube and shake it to clean the ink from inside.
Before putting the batteries and resistor inside the marker tube, insulate all the connections. The tube is aluminun and can create a short circuit between conections. I use hot glue for this.
Now, to make the presure LED first you have to drill the tip so the led can go through with no effort. Cut the legs length of the led to 3 or 4mm. Now glue the bottom of the led to the top of the button.
Make all the solder needed and then insert the led with the button inside the tip of the marker, be sure its correcltly placed and glue the button there. If everything went right the button is securely attached to the plastic tip, but the led is free to be pushed, pressing the button, and making the led to "glow". Now just screw the tip with the tube and you are done.

Below its an image so you can see the marker, button, wire and led I used.

I hope someone likes the design and make his own!

Any sugestion, question, or anything leave it here. Ill answer as soon as posible.
Bye!

PS: Here is a video of my whiteboard setup and the IR tip pressure pen in action
[youtube]http://www.youtube.com/watch?v=WEyDoEeVfc0[/youtube]

urubos · **Reply #1 on:** August 16, 2008, 11:02:57 PM

This looks really great. Unfortunately my soldering skills are pretty lacking. I would love to buy one of these if you have any available.

benpaddlejones · **Reply #2 on:** August 16, 2008, 11:44:06 PM

Marttyn
Aweseome work.

To help replicate could you advise the supplier and part number (hopefully, an online one) of the switch. So other users can find an equivilent part in their country.

Benpaddlejones

Marttyn · **Reply #3 on:** August 17, 2008, 07:31:54 PM

Quote from: urubos on August 16, 2008, 11:02:57 PM

This looks really great. Unfortunately my soldering skills are pretty lacking. I would love to buy one of these if you have any available.

thanks urubos! Im glad you liked my pen!

i must admit that i didnt think about the trouble it would be to sell this kind of pens...

mainly because of the charger. i cant make "custom" chargers, i just buy premade ones and tell you how to connect the pen to it. for a person who understands some electronics would be pretty easy to connect the charger to the pen and charge the batteries, but for every other human being wont be that simple. of course the process is not difficult, just connect the plug to the pen, the cables of the plug to the charger, and the charger to the USB or AC. but if you dont know what you are doing you can damage the pen, the USB, the charger, or even yourself!
moreover, the charger would make the shipping more bulky and heavy, which means higher price, and more chances of having to pay customs.
right now im looking for a pen with room for 2 AAA batteries (alkaline, non rechargable), and which allows the tip pressure mechanism. this wont take long.
the intresting about using alcaline batteries is the price of the pen will be grately reduced. instaid of 12€/19USD for the pen, would be more like 8€/13USD, and no need for a charger
stay tunned, ill update soon with a new design for the pen.

Quote from: benpaddlejones on August 16, 2008, 11:44:06 PM

Marttyn
Aweseome work.

To help replicate could you advise the supplier and part number (hopefully, an online one) of the switch. So other users can find an equivilent part in their country.

Benpaddlejones

thanks to you to ben! would be an honor if somebody use this idea to make his own pen. unfortunatly i dont know where to buy online this kind of SPST push button. im pretty sure that its available form most electronic suppliers. although i made a small "reserch" to find it online, and here you can buy it: http://www.radioshack.com/product/index.jsp?productId=3014504&cp=2032058.2032230.2032278&allCount=91&fbn=Type%2FSPST&f=PAD%2FProduct+Type%2FSPST&fbc=1&parentPage=family
if you want to see if its available at your local electronic supplier shop i made a picture of the buttons near some leds so you can se the actual size of them.

hope this helps.
bye!

Silly · **Reply #4 on:** November 10, 2008, 01:20:53 PM

Hi Marttyn,

Today I finally got my leds so I could finish my first IR-pen. I used a cheap electric toothbrush from the China shop. It is working and I am pretty please

.
Although I am a complete amateur, I am also interested in trying to make your great design of the tip pressure pen. I found all the parts, but my SPST push button has four short 'legs' (just like the one standing up in the photo that you posted) instead of the two long legs (like all the others in your photo)
How, what and where should I solder the led to the button an so on.
I also don't understand why you used two batteries. I have been reading that if you use one battery you don't need a resistor. Can you explain to me the need of two batteries.

Thanks in advance

Marttyn · **Reply #5 on:** November 10, 2008, 04:09:45 PM

Hi! Im glad you liked my pen!
First, why to use 2 batteries instead of one... its because of the led: the more voltage you apply to it, more is the current that flows, and more currents means more radiant intensity. you can check the datasheet of the led.
this led can stand currents up to 100mA.
If i power the led with a AAA rechargable bat (1.2v) or a alkaline bat (1.5v) the current is not as high as it could be. making some test (and of course ohm law!) i find that the leds will bright at it best at 1.7/1.8v. because i cant get a battery with that voltaje i use 3v (2 alkaline plus 12ohm resistor), or 2.4v (2 rechargable, with 6.8ohm resistor).
OFCOURSE you can light your led with a single AAA bat, with no resistor, and it will work greate anyway. its your choice, depending the space available inside your pen.

to conect the pushbutton you have, first you have to notice that it has 2 leads on the same side, and the other 2 on the opposite. you have to connect either 2, on the same side. the rest is like you know.
hope i was helpful in some way.
bye!

Silly · **Reply #6 on:** November 12, 2008, 01:43:44 PM

Thanks for the explaination

. I am going to give it a try as soon as I can. Thanks again!!!

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Author Topic: DIY: How to make tip pressure IR pen (Read 24972 times)

Marttyn

DIY: How to make tip pressure IR pen

urubos

Re: DIY: How to make tip pressure IR pen

benpaddlejones

Re: DIY: How to make tip pressure IR pen

Marttyn

Re: DIY: How to make tip pressure IR pen

Silly

Re: DIY: How to make tip pressure IR pen

Marttyn

Re: DIY: How to make tip pressure IR pen

Silly

Re: DIY: How to make tip pressure IR pen