Wednesday, August 18, 2021

Battery Testing Jig

 I like to test the batteries I have collected to see whether they still have any life left in them before sending them to be recycled. This can be a tedious process, so I wanted to make part of the process easier.

This battery testing jig uses a foot pedal (doorbell button) to activate a solenoid (powered by 4 AA batteries). This pulls the battery into place between the solenoid and a screw at the other end. This connects the battery to my multimeter, without having to hold a lead in each hand while simultaneously trying to look at the multimeter. I can then sort the batteries according to the results.

Testing Jig

Foot Pedal




Monday, August 9, 2021

The Two-Timer


This project started out as just a battery replacement, but then I was inspired by a dad joke to make a dual timer. The goal was to convert the timer to use AA batteries, because they are easier to find than button cell types. 

I added a new battery compartment that's shared by both timers and a new speaker for one of them. One of the timers had more problems. It had a loose connection, which I had been able to fix with a shim at first. But after adding it to the project, it turned into a broken solder connection on the board. After I fixed it, it was still a bit loose so it still needed a shim. Now it's OK when the cover is screwed on.

After attaching the new battery compartment, I glued the parts to a board and added magnets so it can stick to the refrigerator.


Tuesday, August 3, 2021

Paper Art Collage- from the archives

 Griffin has always liked making collages. Fabric, paper, wood, or plastic. This series is from about twelve years ago. He stapled sequins, paper, pencil shavings, leaves, and other decorations to squares of paper. This is a good technique for kids to create quilt like designs, without using a sewing machine or globs of glue (if you don't mind look of the staples in the design).