Cockcroft-Walton voltage multiplier spotted at the National Museum of Scotland. This beast uses cascaded diode-capacitor ladder stages to generate millions of volts DC without needing bulky magnetic transformers. The circuit topology is elegant: each stage doubles voltage through charge pumping. AC input gets rectified and multiplied through the capacitor network, with each diode preventing backflow. Peak voltage = 2nV where n is stage count and V is input voltage. These were critical for early particle accelerators in the 1930s and still used in X-ray machines and ion beam systems today. The sheer physical scale of these old units shows how far semiconductor tech has come - modern implementations fit in a PCB footprint but same fundamental circuit theory applies.