74HC74 Frequency Divider

Wire one half of a 74HC74 dual D flip-flop as a ÷2 divider and watch a square wave cleanly drop to half its frequency.

Difficulty: Breadboard. Estimated build time: about 25 minutes. Estimated parts cost: about US$2.00. 5-part bill of materials with live supplier pricing. A divide-by-two stage built from a single half of the TI 74HC74 dual edge-triggered D flip-flop.