Touch screen stylus

[WmRMeyers]

It's much easier to type on the touchscreen on my camera if I use a stylus. I had been using the one on the end of the blue pen in the photo but I wanted a shorter one to keep in the camera bag. I decided to sacrifice one of the pens and attach it to a short stalk.

A piece of bamboo chopstick was fitted with a 6-32 screw and the stylus tip attached. IT DIDN'T WORK; COULDN'T TYPE A SINGLE LETTER.

A little experimentation showed that it would work if I touched the metal sleeve that housed the rubber stylus tip. Apparently these capacitance touch screens need the capacitance of a human body to work.

Then I assembled the stylus "handle" shown from bits found in my personal hardware store. It works just fine. (I may shorten it even more.)

Now, here's what I don't understand... Presumably, the chopstick handle didn't work because the wood is non-conductive. However, the blue pen works fine and the plastic body is non-conductive (I checked with an ohmmeter), nor was I touching the metal tip or pocket clip while using it.

To further confound the situation, the metal sleeve that holds the rubber tip has a (presumably non-conductive) plastic insert into which the attachment screw(s) thread; there is no metal-to-metal connection between the sleeve and handle.

Marv, what is a capacitor? Two plates with a dielectric material between them, and a charge on the plates, right? You're essentially playing with the characteristics of the dielectric material in your "capacitor." Maybe the bamboo is too good an insulator, or maybe it has too much leakage. Do you have a meter with a capacitance checker? You might be able to measure the differences.

Bill