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Dividing circuit?

J

John Craig

Jan 1, 1970
0
I am building a free pendulum clock, and am hoping to get pulses at
the rate of one per second from a photoelectric cell in the path of
the pendulum.
Where can I find a circuit which will count these, and give out a
signal after 30 pulses?
This would be used to drive the clock hands, and also power a magnet
to keep the pendulum swinging.
Thanks for any help,
John
 
T

Terry Pinnell

Jan 1, 1970
0
John Craig said:
I am building a free pendulum clock, and am hoping to get pulses at
the rate of one per second from a photoelectric cell in the path of
the pendulum.
Where can I find a circuit which will count these, and give out a
signal after 30 pulses?
This would be used to drive the clock hands, and also power a magnet
to keep the pendulum swinging.
Thanks for any help,
John

This should do what you want:

http://www.terrypin.dial.pipex.com/Images/Pendulum-Divide30.gif

Choose mono RC values to suit your needs. Drive next stage via
transistor or relay as appropriate. Supply can be 4 to 16 V.
 
F

Fred Bloggs

Jan 1, 1970
0
I am building a free pendulum clock, and am hoping to get pulses at
the rate of one per second from a photoelectric cell in the path of
the pendulum.
Where can I find a circuit which will count these, and give out a
signal after 30 pulses?
This would be used to drive the clock hands, and also power a magnet
to keep the pendulum swinging.

Assuming the photocell is blocked by the pendulum, and that the output
pulse is less than ten pendulum ticks, you can do something like this.
Use the quad Schmitt NAND to square up the inputs and timing for most
reliable operation:
View in a fixed-width font such as Courier.

..
..
..
..
.. Vdd
.. |
.. ---
.. | / |
.. | \ | PC
.. | / |
.. | \ |
.. --- CD4093
.. | __
.. +----------| \
.. | | o---+---------->>--+ ~ 0.7 x RT1 x CT1
.. | +--|__/ | |
.. [Rp] | | | -> <-
.. | +----------|-------+ | ---
.. | CT1 | __ | | | |
.. | +--||--+-| \ | | CLOCK | |
.. | | | o-+ | -- ---
.. +----[RT1]--+-[220K]-|__/ |
.. | |
.. GND |
.. |
.. +------------------------+
.. |
.. |
.. |
.. |
.. | +---4017---+ +---4017---+
.. +->>--|CK Q0| +--------------|CK Q0|
.. | | | | |
.. | . | | | Q1|
.. | . | | | . |
.. | . | | | Q2|
.. | | | | |
.. +--|MR Q9| | +--|MR Q3|--+
.. | |__ | | | |__ | |
.. +--|EN | | +--------|--|EN | |
.. | | | | | | | | |
.. | | CARRY | | | | | CARRY | |
.. | +----------+ | | | +----------+ |
.. | | | | | |
.. | +--------+ | | |
.. | | | |
.. | | | |
.. GND --------+--------------------+ | |
.. | |
.. +------[10K]-------------------------------------+
.. | |
.. | __ CD4093 |
.. +--| \ |
.. | | o---+ | ---------
.. Vdd--+-----|__/ | | | |
.. | | === | | |
.. | | +|CT2 | --- ---
.. | | 1N4148 | |
.. | +--|<|-----|--------------------+----> PULSE OUT
.. | | __ |
.. +-----[RT2]---+--[220K]-| \ |
.. | | o------+
.. +-----------------------|__/
..
..
..
..
 
F

Fred Bloggs

Jan 1, 1970
0
Fred said:
I am building a free pendulum clock, and am hoping to get pulses at
the rate of one per second from a photoelectric cell in the path of
the pendulum.
Where can I find a circuit which will count these, and give out a
signal after 30 pulses?
This would be used to drive the clock hands, and also power a magnet
to keep the pendulum swinging.


Assuming the photocell is blocked by the pendulum, and that the output
pulse is less than ten pendulum ticks, you can do something like this.
Use the quad Schmitt NAND to square up the inputs and timing for most
reliable operation:
View in a fixed-width font such as Courier.

.
.
.
.
. Vdd
. |
. ---
. | / |
. | \ | PC
. | / |
. | \ |
. --- CD4093
. | __
. +----------| \
. | | o---+---------->>--+ ~ 0.7 x RT1 x CT1
. | +--|__/ | |
. [Rp] | | | -> <-
. | +----------|-------+ | ---
. | CT1 | __ | | | |
. | +--||--+-| \ | | CLOCK | |
. | | | o-+ | -- ---
. +----[RT1]--+-[220K]-|__/ |
. | |
. GND |
. |
. +------------------------+
. |
. |
. |
. |
. | +---4017---+ +---4017---+
. +->>--|CK Q0| +--------------|CK Q0|
. | | | | |
. | . | | | Q1|
. | . | | | . |
. | . | | | Q2|
. | | | | |
. +--|MR Q9| | +--|MR Q3|--+
. | |__ | | | |__ | |
. +--|EN | | +--------|--|EN | |
. | | | | | | | | |
. | | CARRY | | | | | CARRY | |
. | +----------+ | | | +----------+ |
. | | | | | |
. | +--------+ | | |
. | | | |
. | | | |
. GND --------+--------------------+ | |
. | |
. +------[10K]-------------------------------------+
. | |
. | __ CD4093 |
. +--| \ |
. | | o---+ | ---------
. Vdd--+-----|__/ | | | |
. | | === | | |
. | | +|CT2 | --- ---
. | | 1N4148 | |
. | +--|<|-----|--------------------+----> PULSE OUT
. | | __ |
. +-----[RT2]---+--[220K]-| \ |
. | | o------+
. +-----------------------|__/
.
.
.
.

If the PULSE OUT is long, then you may need to add a fast recovery diode
to the output monostable:
View in a fixed-width font such as Courier.

..
..
..
..
.. Vdd
.. |
.. ---
.. | / |
.. | \ | PC
.. | / |
.. | \ |
.. --- CD4093
.. | __
.. +----------| \
.. | | o---+---------->>--+ ~ 0.7 x RT1 x CT1
.. | +--|__/ | |
.. [Rp] | | | -> <-
.. | +----------|-------+ | ---
.. | CT1 | __ | | | |
.. | +--||--+-| \ | | CLOCK | |
.. | | | o-+ | -- ---
.. +----[RT1]--+-[220K]-|__/ |
.. | |
.. GND |
.. |
.. +------------------------+
.. |
.. |
.. |
.. |
.. | +---4017---+ +---4017---+
.. +->>--|CK Q0| +--------------|CK Q0|
.. | | | | |
.. | . | | | Q1|
.. | . | | | . |
.. | . | | | Q2|
.. | | | | |
.. +--|MR Q9| | +--|MR Q3|--+
.. | |__ | | | |__ | |
.. +--|EN | | +--------|--|EN | |
.. | | | | | | | | |
.. | | CARRY | | | | | CARRY | |
.. | +----------+ | | | +----------+ |
.. | | | | | |
.. | +--------+ | | |
.. | | | |
.. | | | |
.. GND --------+--------------------+ | |
.. | |
.. +------[10K]-------------------------------------+
.. | |
.. | __ CD4093 |
.. +--| \ |
.. | | o---+ | ---------
.. Vdd--+-----|__/ | | | |
.. | | === | | |
.. | | +|CT2 | --- ---
.. | | 1N4148 | |
.. | +--|<|-----|--------------------+----> PULSE OUT
.. | | |
.. | 1N4148 | |
.. +-----|<|-----+ |
.. | | __ |
.. +----[RT2]----+--[220K]-| \ |
.. | | o------+
.. +-----------------------|__/
..
 
G

Guy Macon

Jan 1, 1970
0
John said:
I am building a free pendulum clock, and am hoping to get pulses at
the rate of one per second from a photoelectric cell in the path of
the pendulum.
Where can I find a circuit which will count these, and give out a
signal after 30 pulses?
This would be used to drive the clock hands, and also power a magnet
to keep the pendulum swinging.
Thanks for any help,

I just noticed that Mr Craig posted this twice; once to
sci.electronics.design and once to alt.horology. If I
had been aware of this I would not have replied to the
post in alt.horology.
 
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