

Murmuring Merlin
Building Alert: Construction Issues
The tactile switches that we use in this project have very tiny leads that are meant to be surface mounted in an assembly line. Given that we (and you) don’t have an assembly line handy, we used needlenose pliers to crimp wire around the tiny leads to hold the wires in place while we soldered them. The DB9 connector has a small metal tube or cup to which you can solder each wire connection. We found that the easiest way to solder a wire to one of these tubes is to melt some solder into the tube, reheat the tube, and then insert the bare wire end into the melted solder.
When inserting electrolytic or tantalum capacitors into the breadboard, pay attention to the polarity. Inserting the capacitors the wrong way could damage the capacitors and possibly other components in your circuit. The longer lead of the capacitor is the + side. The schematic shows you which direction to insert the capacitor. For example, the + lead of capacitor C2 goes toward Pin 1 of IC2, and the other lead goes toward Pin 3 of IC2. In order to feed wires from the tactile switches to a location where they could be connected to the electronics box by the shortest path, we had to cut a few holes in the fabric of the puppet. Don’t worry; he won’t feel a thing.