Four electronics experiments

Campaigns71–74. Full programs, original editable SVG and PNG figures, and blank observation CSVs are included. Local host checks do not establish physical measurements or target execution.

1. 71 — CD74HC85E: Compare Two Four-Bit Numbers Without Subtracting
2. 72 — MCP41010: A Digital Potentiometer Has a Wiper Resistance and an Endpoint
3. 73 — SN74HC4040N: Divide a Clock and Catch a Ripple Counter Between States
4. 74 — AS5600: A Valid Magnet Still Does Not Count Every Turn