need a simple digital clock circuit


Joined Apr 27, 2007
I remember that there was one chip with almost all the circuitry needed for a digital clock. Only the LCD/LED display, the buttons and the PSU (of course) were to be added. But I don't remember the reference.


Joined Jan 10, 2007
You could try with the LM8562 - Digital Alarm Clock. It also contains an 7 segment display output and alarm.
Edit:I did a search and didn't found a supplier for the LM8562, but you could try with the DS1302 from Maxim IC's.


Joined Jan 22, 2004
check this out

if your not keen on micros maybe you can try several chips like;

7400 - TTL quad nand
7473 - TTL JK Flip Flop
7447 - TTL BCD 7 segment Decoder/Driver
7413 - TTL Dual 4 input Schmitt Trigger (if you could still find one)
7490 - TTL Decade & Binary Counters

however this functions in a 24 hr. mode


Joined Apr 20, 2004
That may be, but the chip was the first LSI ic. It was in a Heathkit digital alarm clock that also used Sperry-Rand displays that were a neon seven segment equivalent of a Nixie tube. After 35 years, it may be hard to find.