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From: josegidayfin on 21 Nov 2008 11:38
hi
i build a bcd clock shown in the page
http://ourworld.compuserve.com/homepages/Bill_Bowden/clock.htm
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
From: Jasen Betts on 21 Nov 2008 16:14
On 2008-11-21, josegidayfin(a)gmail.com <josegidayfin(a)gmail.com> wrote:
> hi
> i build a bcd clock shown in the page
> http://ourworld.compuserve.com/homepages/Bill_Bowden/clock.htm
> 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?

you don't need a 60 Hz frequency, (if you want to see how
controversial they can be look here
http://groups.google.com/group/sci.electronics.basics/browse_thread/thread/7ac304221029c757
)

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
( www.fairchildsemi.com/ds/CD/CD4060BC.pdf#page3 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)


From: David L. Jones on 21 Nov 2008 16:31
On Nov 22, 2:38 am, josegiday...(a)gmail.com wrote:
> hi
> i build a bcd clock shown in the pagehttp://ourworld.compuserve.com/homepages/Bill_Bowden/clock.htm
> 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?

The old way is with a MC5369 chip
http://www.elecfree.com/electronic/wp-content/uploads/2008/08/circuit-60hz-clock-pulse-generator.jpg
But I think that device is discontinued.

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

Dave.
From: Michael Black on 21 Nov 2008 16:39
On Fri, 21 Nov 2008, David L. Jones wrote:

> On Nov 22, 2:38 am, josegiday...(a)gmail.com wrote:
>> hi
>> i build a bcd clock shown in the pagehttp://ourworld.compuserve.com/homepages/Bill_Bowden/clock.htm
>> 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?
>
> The old way is with a MC5369 chip
> http://www.elecfree.com/electronic/wp-content/uploads/2008/08/circuit-60hz-clock-pulse-generator.jpg
> But I think that device is discontinued.
>
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

> Otherwise you need a suitable frequency oscillator and a divider
> circuit to get 60Hz.
>
> Dave.
>
From: John Fields on 22 Nov 2008 11:04
On Fri, 21 Nov 2008 08:38:41 -0800 (PST), josegidayfin(a)gmail.com wrote:

>hi
>i build a bcd clock shown in the page
>http://ourworld.compuserve.com/homepages/Bill_Bowden/clock.htm
>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?

---
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.

http://www.ecsxtal.com/store/pdf/ecs-31x.pdf

JF
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