Bulova Accutron 2180 2181

[Plato]

18 hours ago, JohnR725 said:

I somehow doubt that that's the problem as I've never heard of that before. We really need a picture.

I think I'll test my theories in the future before guessing the outcome. I tried a 343, 344 and 350 in a spares movement and the outcome was the same each time - I could get each battery to not start.

I might try and investigate the capacitor(s) next...

 

[JohnR725]

1 hour ago, Plato said:

I could get each battery to not start.

Just a clarification so things are clear in my mind. Just to be clear on things you do know that the watch is not necessarily a self-starter. In other words I'm going to snip something out of the service manual for the 218. Notice the reference that you have to give it a start. So in other words it's not a 100% the watch will start with power it sometimes needs a little help and the manual was written with the thought of using a Mercury battery.

[Plato]

5 minutes ago, JohnR725 said:

Just a clarification so things are clear in my mind. Just to be clear on things you do know that the watch is not necessarily a self-starter. In other words I'm going to snip something out of the service manual for the 218. Notice the reference that you have to give it a start. So in other words it's not a 100% the watch will start with power it sometimes needs a little help and the manual was written with the thought of using a Mercury battery.

So there may be nothing wrong with a tuning fork watch that doesn't start each and every time? Just a quirk of that type of movement? 

[JohnR725]

11 minutes ago, Plato said:

So there may be nothing wrong with a tuning fork watch that doesn't start each and every time? Just a quirk of that type of movement? 

Yes exactly there's nothing wrong with the watch.

[Plato]

36 minutes ago, JohnR725 said:

Yes exactly there's nothing wrong with the watch.

Thanks @JohnR725. I have two nice Omegas that I didn't feel right to sell on thinking they had a problem. I was happy to keep and wear them knowing full well that a little tap would see them run but not good enough for sale. I'm going to keep one and sell the other to fund more projects 

[markr]

What is a good variable power supply for working on Acutrons?

[LittleWatchShop]

54 minutes ago, markr said:

What is a good variable power supply for working on Acutrons?

If you want to build it yourself, here is a solution that I found on the web a while back.

I built a simpler variable power supply to work on quartz watches.

[JohnR725]

1 hour ago, LittleWatchShop said:

If you want to build it yourself, here is a solution that I found on the web a while back.

If I remember right the person of posted this design adapted a Bulova variable power supply which is why it's such a peculiar design.

Then if you're looking for another idea of the simple design here's what I use.

lm10.pdf

[markr]

Is there one I could buy that would work?

5 hours ago, JohnR725 said:

If I remember right the person of posted this design adapted a Bulova variable power supply which is why it's such a peculiar design.

Then if you're looking for another idea of the simple design here's what I use.

lm10.pdf 2.59 MB · 0 downloads

I might be able to build this if I knew what that thing in the middle was.

[Kalanag]

It‘s an operational amplifier.

[LittleWatchShop]

You can get an lm10 from a host of places...Jameco, digikey, mouser, etc.

Let me know if I can help you build it.

[markr]

Sorry for late response.  My computer is f upped and wont let me download photos.  Will this meter work and can I build the power supply in it?  Is the power source a 9v battery?  What controls the voltage amount?  I think that I can build it with a little help.

[LittleWatchShop]

16 minutes ago, markr said:

Will this meter work and can I build the power supply in it?

No, the voltage range is too high.  Your power supply maximum voltage is less than two volts.  Now for me, I would build a supply that goes to about 3.2 volts because it would be more general purpose for quartz watches.  But 10 volts is way too high.

The circuit @JohnR725posted is fine for your application.  I would use a digital meter if your only goal is to provide voltage (not measure current).  I will sketch something up for you and post it a little later.

 

[LittleWatchShop]

Use this for your volt meter.

Shown here is a schematic and a layout.  I did not try to make this compact so it is laid out very loose.

Check my work...cranked out pretty fast.

You can download the software used to generate these and order them online.  You get three boards for about $60.  US made and very high quality.

In this layout, the Meter and pot are not intended to be placed on the PCB but shown this way for checking purposes.

The bypass caps are overkill.

If you want to build this, I can PM you the files and a link to the fab.

Edited August 2, 2022 by LittleWatchShop

[JohnR725]

3 hours ago, LittleWatchShop said:

No, the voltage range is too high.  Your power supply maximum voltage is less than two volts.

Yes the problem of normal power supplies are not meant to do watch repair. They will not go typically low enough voltage sometimes a well. They typically go way too high and voltage. Plus they have way too much power out and if you short the leads together you'll have smoke and fire. None of which are nice to have on the watch bench.

 

 

[markr]

Thanks.  I may have someone to help me with this and he may have some parts for me. I'm sure I'll be back with some questions like what is the power source?

[LittleWatchShop]

Here is my power supply.  I use a 9V battery inside the box.  The circuit in this box is different than the one posted above.  The box is a stock box, but the front plate was 3D printed.  I had the 10-turn pot in my box-o-parts, so I used it, but it could be a standard pot.

Here is a tighter layout...just because...

The dots are 0.1 inch spacing.

[LittleWatchShop]

I just ordered some boards and LM10.  Will report back on this next week.

[LittleWatchShop]

My boards arrive today.  I have the parts already.  Maybe later today, I will post the assembled unit...stay tuned!!

[LittleWatchShop]

Here it is...working.  There is a mistake in the pcb layout.  I cannot believe it. What a dip***t mistake.  Who can find it?

 

[HectorLooi]

1 hour ago, LittleWatchShop said:

Here it is...working.  There is a mistake in the pcb layout.  I cannot believe it. What a dip***t mistake.  Who can find it?

 

I don't know if it's a mistake, but I would have reversed the top and bottom layers of the tracks for easier soldering.

[LittleWatchShop]

1 hour ago, HectorLooi said:

I don't know if it's a mistake, but I would have reversed the top and bottom layers of the tracks for easier soldering.

No, that is not it.  These are plated through holes (vias), so soldering from either side works just fine.  There is a more fundamental error.

[LittleWatchShop]

On 8/1/2022 at 1:42 PM, markr said:

Sorry for late response.  My computer is f upped and wont let me download photos.  Will this meter work and can I build the power supply in it?  Is the power source a 9v battery?  What controls the voltage amount?  I think that I can build it with a little help.

If you want to build the LM10 supply, I will send you the PCB.  You can order the LM10 from a variety of places and the digital meter also if you wish to use it.  The 5K pot is also available at Jameco

Edited August 11, 2022 by LittleWatchShop

[markr]

That will be great. I'll PM you.

[HectorLooi]

23 hours ago, LittleWatchShop said:

No, that is not it.  These are plated through holes (vias), so soldering from either side works just fine.  There is a more fundamental error.

So what's the mistake?

The solder pad of R1 looks strange and the alignment of the holes of C1, R1 are not in a straight line. I don't know what the underside looks like but it doesn't seem to follow the PCB plan.