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Infra-Red Pen Using Internal Battery and Marker Housing
Submitted By: Janine
Date: 05/25/2008
I work in an Winnipeg, Canada elementary school and eventually these pens will be in little hands. For that reason, I didn’t like the idea of an external battery, so I used a marker casing instead of a pen so I’d have room to slide the battery inside. It worked beautifully.
So far, I’ve made 4 pens, these pics are from the first two. The yellow pen was my first attempt. The red one works better – I had the chance to make a few changes to address some problems I’d had.
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It was a fairly simple procedure – anyone could do this…no need for any specialized skills. I started by emptying the marker casing. The yellow pen had an end-cap that I just pulled off and replaced when I was done. For the red pen, I had to cut off the end – I used the cap as a cover for the battery on the finished product. To get the switch in without cutting the whole length of the pen, I cut holes through the casing (with that all-purpose tool, the Swiss Army knife) and then slipped the switch in after I’d connected the wires.
It took a bit of fiddling around (and it's a bit of a mess of wires inside...), but it was worth it in the end. I got a nice, clean, safe pen that I can hand over to 4 and 5 year old children.
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For the yellow pen, I just covered over the hole on the back of the barrel with duct tape (Red Green would be proud…). The red pen gave a much more aesthetically pleasing result. It had a rubber grip that I just peeled back to insert the switch, then pulled back over when I was done. Very nice. Another thing about the marker casings that I liked is that a 5mm LED bulb just fits snugly through the opening where the marker tip was removed. A bit of hot glue through the hole I cut for the switch stopped the bulb from pushing back into the casing.
Both of the pens in these pictures have the contacts to the battery held in place by electrical tape. As you might guess, this is not a satisfactory plan. The contacts have a nasty habit of failing every time the pen is dropped. Pens #3 and #4 are in the same type of casing as the red one – the only major difference is in the battery contacts. Pen #3 has the wires soldered on to the battery (had a bit of trouble with this, but a friend set me straight on what I was doing wrong – thanks Mike). For pen #4, I used a AAA battery holder filed down to fit into the marker casing. I think this is probably the solution I’ll go with for any future pens, as it makes changing the battery much easier.
So, there you have it - Janine’s IR pen making adventures.
I appreciate that there are folks like you who are willing to share what they know to make things easier for folks like me who are still struggling with some aspects of the ever-changing world of technology that we live in. I’m a babe in the woods with some of this stuff – it’s nice to know there’s always a friendly guiding hand around when a bit of guidance is needed.
--Thanks Janine for sharing your ideas and also for bringing the world of electronics to the little ones. I wish I had a teacher like you when I was in kindergarden! -- Vas @ Terracode
Please e-mail info@terracode.com with any comments or questions.
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