This digital countdown timer displays remaining time set for a deadline/event. The USP of this project is that it is built without using any microcontroller unit. So, It is about going through a fair journey to hardcore digital electronics involving concepts of clock, counter, and digital logic design.
Bill of Material:
| Product Name | Manufacturer | Quantity | Buy Now |
|---|---|---|---|
| CRYSTAL, 32.768KHZ, 12.5PF, CYLINDER | ABRACON | 1862377 | Buy Now |
| 7 Segment LED Display, Mechanically Rugged, Red, 20 mA, 8 V, 55.5 mcd, 1, 56.9 mm | KINGBRIGHT | 1168637 | Buy Now |
| Ripple Carry Binary / Divider, CD4000 Family, 24 MHz, 3 V to 18 V, DIP-16 | TEXAS INSTRUMENTS | 3119758 | Buy Now |
| Logic IC, OR Gate, Quad, 8 Inputs, 14 Pins, DIP, 7432 | TEXAS INSTRUMENTS | 3006469 | Buy Now |
| BCD to 7 Segment Decoder / Driver / Latch, 1 Gate, 4 Input, 7 Output, 6.8 mA, 3 V to 18 V, DIP-16 | TEXAS INSTRUMENTS | 3119855 | Buy Now |
| Binary / BCD Up / Down Counter, 11 MHz, 3 V to 18 V, DIP-16 | TEXAS INSTRUMENTS | 3006272 | Buy Now |
| Flip-Flop, Complementary Output, Positive Edge, CD4013, D, 45 ns, 12 MHz, 6.8 mA, DIP | TEXAS INSTRUMENTS | 3119947 | Buy Now |
| Logic IC, AND Gate, Triple, 3 Inputs, 14 Pins, DIP, 74LS11 | TEXAS INSTRUMENTS | 3120530 | Buy Now |
Additional Parts:
| Product Name |
|---|
| 9V 3A DC power supply |
| Soldering station |
| Breadboard |
| LED indicators |
| resistors |
| push button |
| 2-way switch |
DIY Discrete Logic LED Countdown Timer
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