Exploding capacitor This was a 100µF, 25V electrolytic capacitor reverse connected to a 40V power supply. Jacob's Ladder The high voltage was generated from a line output transformer liberated from an old crt television. The transformer was driven with a square wave from a 60V supply at a frequency of 2-3kHz. The circuit produced sparks of around 4cm length at the top of the ladder. The sound heard is from the ionised air, the frequency being the switching frequency of the transformer. Capacitor charging at constant current A capacitor (~900µF) is charged at a constant current (~0.36mA). The voltmeter indicates the how the potential difference across the capacitor varies with time. This video accompanies Capacitor charging with constant current. The high resolution version of this video (~100MB) is available on request.

Over heated resistor This was a 10Ω, 0.25W carbon film resistor, connected to a 12V power supply. 5A fuse failing The 5A fuse was connected in series with a 2Ω resistor and ammeter to a variable low voltage power supply. The fuse is shown just below the ammeter scale. The video starts at a current of 4.1A and the current is then slowly increased until the fuse fails. Note that the 5A fuse fails at more than its rating - this is because the overload occurred slowly, allowing the fuse wire to dissipate some of the heat generated. Had the overload occurred quickly then the fuse would have failed nearer to its rated value.