pulse generator to trigger a slave clock

[PietBos]

Hello,
I have a slave clock which requires an impuls every minute to advance the movement one step.
The characteristics of the clock are simple.
A pulse of 24 Volts advances the clock one step.
To make the next step the pulse should be applied to the same contacts but with reverse polarity.
Does anyone have a suggestion how to tackle this problem with an Uno board.
It is my idea to use two monostable relays, either relay wil have their own output on the uno board.

Hope someone can help me.

best regards Pieter.

[sonnyyu]

http://forum.arduino.cc/index.php?topic=10221.0

[dwightthinker]

I picked up one of the DS3231 modules on ebay. These are good to
+-2 mins a year.
Use a couple relays.
The DS3231 can be used to put out a 1 second pulse. You can
use it to run an interrupt or just poll the pin.
You could use a single source, a double throw double pole and
a single pole single throw together do what you need. Remember,
the clock doesn't care which lead it ground, just that the polarity switches.
Do note that most of these clocks are pulse for at most 1 second,
some less than that.
Dwight

[eathan21th]

Hi,
I just use an "arduino uno" + "Arduino Motor Shield L293D" + "24V DC adapter" to drive my seiko slave clock which also need the same signal like yours. And the clock works great now.

Remember to make sure the C7/C8 capacitors on  "Arduino Motor Shield L293D" can support at least 25V.

Connections, green line and yellow line are ontput of L293D, these 2 lines are connected to slave clock.


Waveform, the pulse-width is adjustable.



BR,
Eathan

[eathan21th]

Hi,
I just use an "arduino uno" + "Arduino Motor Shield L293D" + "24V DC adapter" to drive my seiko slave clock which also need the same signal like yours. And the clock works great now.

Remember to make sure the C7/C8 capacitors on  "Arduino Motor Shield L293D" can support at least 25V.

Connections, green line and yellow line are ontput of L293D, these 2 lines are connected to slave clock.


Waveform, the pulse-width is adjustable.



BR,
Eathan

Updated,
After several moths test, finally I added a DS3231 RTC module to the board due to the low accuracy of the Arduino internal timer, about 400~500ppm.

With the RTC module, the slave clocks driven by the boards become much more accurate.