Re-inventing the scale.

Must have been a long winter stuck inside to try something like this. The idea was to make a scale using a couple of pennies and conductive foam used for packing electronic parts. The first thing was to solder some wire onto pennies. I used a torch instead of a soldering iron because pennies can soak up a lot of heat.

Pennies with hookup wire soldered to them. Foam is packing from a power MOSFET.

The next step was cut some plexiglass sheets and then use some double stick tape to attach a penny to each sheet. Then I bolted the two sheets together, presssing the foam in between. Here’s the assembled unit.

Platform assembled, and hooked up to ohmmeter to test base resistance.

This setup didn’t work out so well as a scale. Heavier objects placed on the scale took a long time to reach a stable value. I figure that the foam continued to compress slightly for two minutes or more. Also, it took a similar amout of time for the scale to return to it’s base value.

This arrangement seems to work best not as a scale, but as a pressure pad, particularly as a pressure-relief pad. For example, it might work well to sense when an object, such as a book, is lifted. Don’t anyone dare try to steal my “Programming Python book!”