Clock Controller

[jcarruthers]

Hi All,


I've got an old Solari wall clock - huge thing that you see in train stations etc

I got it "working" this morning by attaching a 6v power adapter - changing the polarity makes the clock work. It needs to go from +/- to -/+ to make the clock count "up" - uses an electromagnet to turn a weighted disc.

So what I need is an accurate timer circuit that will pulse every minute and go from +/- to -/+ - it can be off - then do the swapping polarity thing.

Any ideas? I don't think a 555 will be accurate enough for this...?


James

 

[blueroomelectronics]

An RS485 driver will flip polarity, so will an H-Bridge (try robotroom.com for H-Bridge stuff)
The 555 is not nearly accurate enough for a clock.

 

[ericgibbs]

Hi All,


I've got an old Solari wall clock - huge thing that you see in train stations etc

I got it "working" this morning by attaching a 6v power adapter - changing the polarity makes the clock work. It needs to go from +/- to -/+ to make the clock count "up" - uses an electromagnet to turn a weighted disc.

So what I need is an accurate timer circuit that will pulse every minute and go from +/- to -/+ - it can be off - then do the swapping polarity thing.

Any ideas? I don't think a 555 will be accurate enough for this...?


James

Hi,
I would suggest you PM, the forum member 'wombweller' , we are currently working on external pulsing of 'older' clocks.

A 555 is no where accurate enough for long period real time applications.

Have a look at the HEF4060, using a 32.768KHz xtal, you may need an extra divider to get the 60sec interval.

 

[jcarruthers]

Thanks guys...

Here's a photo of the device - for your reference

 

[crutschow]

Have a look at the HEF4060, using a 32.768KHz xtal, you may need an extra divider to get the 60sec interval.

Yes. A HEF4060 is a 14-bit oscillator/counter which would give you 2 pulses per second with a 32,768Hz crystal. You need an additional divide by 120 to get your once per minute pulse which could be done with a programmable counter such as an HEF/CD40103.

 

[Pommie]

There was a long thread on this a while ago. Found it, it is slightly different from what you are trying to achieve but should have some useful information in it.

Mike.

 

[jcarruthers]

Thanks for all your replies.

I think this is all a little beyond me and out of my range. I can put stuff together or even lay it out if given a schematic but I simply don't know enough about binary counters and things to understand it.

Does anyone have any ideas who might be able to make something for me?


James

 

[RODALCO]

Solari

Those are great clocks !!
Cifra 12 is that type.

I have two of them in my house which I run of a Bürk 24 Volts master clock.
These require short (about 1 second) 24 Volts dc, 1 minute impulses every minute and the polarity needs to be changed every time.

To have maximum accuracy, if you run them of an electronic supply, use a crystal oscillator and dividing counter IC, as already suggested by our other members and take off 1 minute impulses to drive an H bridge made of a couple of powertransistors.

I can dig the bridge circuit up if you require it.

Regards, Raymond

 

[RODALCO]

I see that yours is a 6 volts clock, so a 6 volts dc supply is needed. or you need to put a series resistor in line to reduce the voltage.

Some of these Cifra clocks have some voltage select options by means of links which can be set to the required voltage e.g. 12 - 24 or 60 Volts.

Regards, Raymond

 

[jcarruthers]

Hi Raymond,


Any help you can give would be invaluable.

Can you explain to me about the Bürk 24 Volts master clock? Can I buy one or something similar?

Do you mean that the polarity changes every pulse, every minute - with my clock that would mean it would only change every 2 minutes?

Any help with any circuits to get this going would be great!


James

 

[ericgibbs]

Thanks for all your replies.

I think this is all a little beyond me and out of my range. I can put stuff together or even lay it out if given a schematic but I simply don't know enough about binary counters and things to understand it.

Does anyone have any ideas who might be able to make something for me?


James

hi James,
Did you contact 'wombweller' aka Mark.?
We are working together to upgrade 'old clocks', we may be able to help.

Can I ask where you are located, its a good idea to fill in your location, [profile]

 

[jcarruthers]

Hi Eric,

I have to admit I didn't - I looked for contact details but couldn't find them... I must have made a typo as I realise now it's quite easy to find!

I'm in the UK - London to be precise.


James

 

[RODALCO]

Attched is the schematic for the H - bridge.

Also a photo is attached from two Bürk masterclocks, I have 6 of them, and one of my Cifra 12's with blue LED's as enhancement.

These Bürk master clocks are often on sale on Ebay Deutschland (Germany).

Look under Hauptuhr, Mutteruhr.
and check that they have 24 Volt output via mercury switches, visible at the left of the dial.
Some Bürks drive direct 220 Volt tower clocks and are not suitable unless additional relays are added.

In the UK you need to look for an ECS memory masterclock which has alternative output pulses. Often 24 Volts but with a series resistor you can use the 6 volts clock coil ok.

 

[jcarruthers]

Something a bit like this?

**broken link removed**

 

[jcarruthers]

Rodalco,

Can you confirm how to drive my Cifra 12 - everything I've read is different to how I've managed to get it to work.

Mine seems to need two alternating pulses to move the clock forward one minute - where as everyone else seems to describe it as the alternating pulse being every minute (which would make my clock work half speed?!)

 

[RODALCO]

Cifra 12

You say that yours need two alternating impulses to advance the clock one minute ?

e.g. impulse - pos 6 volts, click, neg 6 volts, dial flips, pos 6 volts, click, neg 6 volts dial flips ?? like that ?

That could be a set up for probably a French clock system, some of those use 30 seconds impulses.

Can you make a close up of the actual actuator? which drives the white odd shaped wheel with the 10 curved notches ?

If the actual drive has 1 pin than it is set up for the 30 second pulse.
Can easily be made to accept 1 minute pulses if the wheel has the second hole (which is not used in your case).

There should be a second hole to add an other pin, which makes it suitable for 1 minute impulses.
I have one of those, and simply added a wooden sateh stick in the spare hole, fitted perfectly and the clock runs perfect for over 2 years of my Bürk master clock.

The ebay listed clock is suitable as master clock and has a built in low voltage 12 or 24 volts supply and provides alternating pulses to drive the Cifra 12.

 

[jcarruthers]

Your description is correct... French system would make sense as it was bought at a French flea market...

However.... stop press.... I just found this...

IMP-2 Slave clock Impulser for Brille, Gents, Synchrome, International, Standard Electric and Stromberg Slave Clocks

Not quite so elegant - but seems that it will do the job?

I'll get a close up of the actuator for your curiosity...

 

[RODALCO]

I had an other look at your first photo and it looks that the drive wheel has only one pin. (photo is a bit dark, ok, my 21" monitor is old too)

Add one and your clock will work at the correct speed.

Cheers, Raymond

 

[RODALCO]

Sounds that looks that board does the trick. Worth while a go if it is not too expensive.
Bear in mind posting a master clock is not cheap. I pay 80 to 85 Euro's for shipping to New Zealand for under 20 Kg.
From Germany to the UK probaly 40 Euro's.

Other option to consider is to get two motor driven cam wheels with micro switches from a surplus electronics shop.

One provides an impulse every minute, other one provides an impulse every 2 minutes. By means of a couple of relays added, a clock powersupply can be build from those parts with the mains frequency as long term accurate reference.

 

[wombweller]

Hi Eric,

I have to admit I didn't - I looked for contact details but couldn't find them... I must have made a typo as I realise now it's quite easy to find!

I'm in the UK - London to be precise.


James

Hi James

Well if you can't find me then I will have to find you!!!

I have had many chats on this topic for many different applications.As Eric G. says we have been working together on such projects for sometime now and We have come to some conclusions.I realize for someone who is new to Electronics this may seem a very daunting task but I can say you will find it interesting and the end result very pleasing.

Reading through your posts it seems that you request for someone to make you what you are looking for.So to save time going through schematics and how they work I would suggest contacting.As we are in the same country I may be able to help.

Mark