ALT A schematic from 555 datasheet, explaining that "The duty cycle is on-time expressed in terms of total cycle time. The duty cycle is limited, under normal curcumstances, to 50%. However, by adding a diode a duty cycle of less than 50% can be achieved". A cartoonish man drawn next to the schematic points to the diode symbol.

ALT A schematic for a delayed light turn-off circuit. The schematic is next to a cartoon of a machine where a match burns a rope that drops a rope on top of some bellows that blow out a candle.

ALT A cartoon titled "threshold voltage". Text at the bottom says "When triggered, the timer starts its timing cycle by driving the output, pin 3, high. Simultaneously, the timing capacitor starts charging from its steady state level at ground. When it reaches 2/3 vcc, an internal comparator is tripped, causing the capacitor to discharge toground. This drives the output low, ending the timing cycle". In the cartoon, a man is hanging from a branch on a cliff. The branch is labeled "2/3 VCC"; the top of the cliff is labeled "VCC", and the bottom is labeled "Ground"