Ttl clock
About the Ttl clock PCB
Ttl clock is an open source PCB design by skiselev, published on GitHub under the GPL-3.0 license. It is a 2-layer board measuring 100 × 100 mm, with 60 components from 19 distinct parts.
Other key parts include the 74HCT4060, 74LS00, 74LS47, 74LS90 and DA56-11SRWA. By type, the board carries 19 ICs, 19 capacitors, 7 resistors, 4 diodes, 3 switches and 1 crystal.
It belongs with the displays & leds designs in this gallery.
From the project
74xx ICs Based Digital Clock
The clock uses a 32768 Hz quartz crystal (X1) and 74HC4060 counter/divider IC (U1) to generate 2 Hz signal. This signal is divided further by 2 using a part of 74LS90 counter (U6). The obtained 1 Hz signal is fed to two 74LS90 counters (U11 and U12) that count seconds. The seconds reset circuit implemented using two 74LS00 NAND gates (U4A and U4B). This circuit resets both seconds and tens of seconds counters when they reach "60" or when "SECONDS" switch (SW1) is pressed, allowing seconds adjustment.
Main components on the Ttl clock
Ttl clock bill of materials (BOM)
60 components, 19 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | 74HCT4060 | IC_DIP16_300 | U1 |
| 3 | 74LS00 | IC_DIP14_300 | U2, U3, U4 |
| 6 | 74LS47 | IC_DIP16_300 | U5, U6, U7, U8, U9, U10 |
| 6 | 74LS90 | IC_DIP14_300 | U11, U12, U13, U14, U15, U16 |
| 3 | DA56-11SRWA | DA56-11SURKWA | U17, U18, U19 |
| 1 | 32768Hz | Crystal_32K_Horiz | Y1 |
| 1 | 5V | Conn_Power_Jack_Circular_Pads | P1 |
| 6 | 470 | IC_DIP16_300 | RP1, RP2, RP3, RP4, RP5, RP6 |
| 1 | SECONDS | Switch_SPDP_D2F | SW1 |
| 1 | MINUTES | Switch_SPDP_D2F | SW2 |
| 1 | HOURS | Switch_SPDP_D2F | SW3 |
| 4 | LED | LED_D3.0mm_FlatTop | D1, D2, D3, D4 |
| 16 | 100nF | Cap_Cer_762 | C1, C2, C3, C4, C5, C6, C7, C8 +8 |
| 1 | 100uF | CP_Radial_D6.3mm_P2.50mm | C17 |
| 1 | 12pF | Cap_Cer_508 | C18 |
| 1 | 5-30pF | C_Trim_Murata | C19 |
| 5 | 4.7k | Res_762 | R1, R2, R3, R4, R5 |
| 1 | 330k | Res_762 | R6 |
| 1 | 15M | Res_762 | R7 |
Ttl clock design files
The KiCad project lives in the skiselev/ttl-clock repository on GitHub; these links point at the commit this page was built from.
Ttl clock: common questions
How big is the Ttl clock PCB?
The Ttl clock measures 100 × 100 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the Ttl clock?
60 components, from 19 distinct parts. The full bill of materials is listed on this page.
Where can I download the Ttl clock design files?
From the skiselev/ttl-clock repository on GitHub, which has the KiCad layout; the links under Design files point to each one.
Can I use the Ttl clock design in my own project?
Yes, under the terms of its GPL-3.0 license, which skiselev chose for the repository.
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