binary clock power circuit

Nov 21, 2008 7 Replies

hi i build a bcd clock shown in the page

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and all the circuit works fine but i want to chage the power source of the circuit to dc source. so my question is how can i get a 60Hz frequency from a dc source?



thanks in Advance


you don't need a 60 Hz frequency, (if you want to see how controversial they can be look here

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)

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 (
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page 3 )

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

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The old way is with a MC5369 chip

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But I think that device is discontinued.

Otherwise you need a suitable frequency oscillator and a divider circuit to get 60Hz.

Dave.

page

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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 | | | |16 |8 |12 +--+-----+-----+------------+ | Vcc GND MR | | | | | | RS RTC Q9 | +-+-------------+--------+--+ |11 |10 | +----[1M]-----+ +----->60Hz | | | [1.1M] | | +--[30720Hz]--+ | | [22pF] [22pF] | | +-------------+ | GND

The component values are for an ECS-31X crystal, but will be pretty much the same for any of the tiny tuning fork watch-type crystals out there, I think.

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JF

Oops... The chip is a 4060. JF

2Hz input

fast)

Oh Thank You guys God Bless You

2Hz input

fast)

Oh Thank You guys God Bless You

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