Astable multivibrator using NAND gates

This astable multivibrator uses two NAND gates of the 4 available on the 7400 TTL integrated circuit. Two LEDs are used to view the status or logic output of each gate.

LED Sequencer using 4017 – LED Chaser.

This Circuit has 10 LEDs connected to the 4017 decade counter outputs. LEDs light up in sequence. Only one LED is ON at a time

Clock signal generator using 7400 IC (PCB)

This clock signal generator is an astable circuit which uses the TTL 7400 integrated circuit. The 7400 IC has four 2 inputs NAND gates (NOT AND) but we only use two gates. Suggested Printed Circuit Board (PCB)