hi i build a bcd clock shown in the page
thanks in Advance
hi i build a bcd clock shown in the page
thanks in Advance
you don't need a 60 Hz frequency, (if you want to see how controversial they can be look here
all you need is one pulse per second on pin 1 of the seconds counter. you can get that using the circuit found on the the CD4040 datasheet that uses a crystal by using a 32768Hz crystal and dividing it by
32768, to do that just use a CD4060 (and take 2Hz output from pin 1 of the 4060 to pin 10 of the existing 4040 (disconnect the existing input to that pin)
on the right of the CD4040 chip the circuit then needs to be adjusted for 2Hz input
connect pin 4040 pin 9 to the seconds chip pin 1 (disconnect other wires from there)
the 2 nand gates, inverter and xor gate are not needed but will have no effect on the operation of the circuit (so long as 74hc14 pin 4 is not connected to seconds chip pin 1.
disconnect the seconds and hours set switches from 4040 pin 6 and connect them instead to 4060 pin 1 (or use pin 2 or pin 3 if 1 is too fast)
page
The old way is with a MC5369 chip
Otherwise you need a suitable frequency oscillator and a divider circuit to get 60Hz.
Dave.
page
It was discontinued a decade ago. There were threads back then about replacements. Michael Covington one asked about the simplest solution, and then ran the best result in the Q&A column that he was running in "Electronics Now" around that time.
Michael
-- View in Courier: +5V GND GND
-- Oops... The chip is a 4060.
2Hz input
fast)
Oh Thank You guys God Bless You
2Hz input
fast)
Oh Thank You guys God Bless You
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