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Weishi vs. Vibrograf conflicting results

LittleWatchShop
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xyzzy WRT Addict

xyzzy

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On 11/11/2021 at 4:07 AM, LittleWatchShop said:

So...how does this thing work?  Well, the motor spins at a precise speed.  The motor drives a roller that his a raised spiral.  When the watch ticks, it causes a hammer to impact the roller.  If the impact hammer hits the roller at the same angular position each time, a vertical line will be marked on the paper.  If the impact hammer hits the roller at a different angular position, the line will walk to the left or to the right. 

From the photo of the tape of a watch running slow, I gather that the motor spins from right to left?

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nickelsilver Distinguished Member

nickelsilver

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52 minutes ago, xyzzy said:

From the photo of the tape of a watch running slow, I gather that the motor spins from right to left?

I'm sure the motor runs in a circle.

 

Sorry, haha. I haven't run my b200 in many years, as I recall looking down at the roller, with the upper part of the spiral to the left, it continues downward towards the right.

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LittleWatchShop Distinguished Member

LittleWatchShop

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27 minutes ago, nickelsilver said:

I'm sure the motor runs in a circle.

 

Sorry, haha. I haven't run my b200 in many years, as I recall looking down at the roller, with the upper part of the spiral to the left, it continues downward towards the right.

That is correct. It is a raised helix. Very clever design.

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JohnR725 Distinguished Member

JohnR725

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53 minutes ago, LittleWatchShop said:

is the 5meg board from a B200a?

Absolutely no idea at all?

Went back to the folder where the photograph was found and the only thing I photographed was that office later board and the serial number plate. At least I'm guessing that would be the machine it came from.

B200 sn for new osc.JPG

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LittleWatchShop Distinguished Member

LittleWatchShop

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18 minutes ago, JohnR725 said:

Absolutely no idea at all?

Went back to the folder where the photograph was found and the only thing I photographed was that office later board and the serial number plate. At least I'm guessing that would be the machine it came from.

B200 sn for new osc.JPG

The one I have...guessing my Dad bought it in the early 70s. Before that, he had a Watchmaster.

when I get back home, I plan to measure the speed of the motor, and check to see which crystal board I have.

Edited by LittleWatchShop
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xyzzy WRT Addict

xyzzy

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On 11/12/2021 at 10:59 AM, nickelsilver said:

Sorry, haha. I haven't run my b200 in many years, as I recall looking down at the roller, with the upper part of the spiral to the left, it continues downward towards the right.

That's the opposite of what I thought.  But, the tape moves "up", I was thinking down, so from the left to the right.  So the line will move to the right as it goes down if the movement is slow.

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LittleWatchShop Distinguished Member

LittleWatchShop

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OK, indeed the motor spins at the following speeds: 32, 40, 44, 48 RPS.  I verified this by measuring the motor pulses with an oscilloscope.

The gear ratio to the platen (the rotating cylinder) is 2.666:1 (the motor turns 2.3333 times for every rotation of the platen).

There are two oscillations of the helix on the platen for every rotation, thus the effective gear ration with respect to the helix is 1.333:1

Taking the ratio of the motor speed to the helix frequency yields 24, 30, 33, 36 which are the values at the top of the beat table on the B200 and designated as "N" in the document posted above. 

These numbers comport with the numbers I posted originally where I assumed that the platen and the helix were 1:1 and the motor to platen also 1:1

And finally, the divider values to achieve the motor frequencies are 330, 264, 240, 220.

There is harmony in the universe.  I can now move on to the next problem...

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JohnR725 Distinguished Member

JohnR725

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I was probably making a incorrect assumption which was that the vacuum tube version the B100 probably Has the same print mechanism but I don't know if it really does.

What's interesting about the company who makes the timing machine is that the earlier versions they have schematics and repair Manual with all the variations of the schematics and a complete parts list which is not entirely helpful as some of the parts a course or their part numbers and do not correspond to anything in the real world. Like for instance the crystal pickup.

What I was curious about was whether the a use the same quartz frequency they did not. Then because it's vacuum tubes they use a three stage divider and came up the frequencies that I snipped out down below.

 

B100 _motor fr.JPG

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JohnR725 Distinguished Member

JohnR725

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29 minutes ago, LittleWatchShop said:

I don't understand what this snip means. 

It means I was being lazy and only snipped out one item and didn't give you the other item which I'm now giving you. What the snippet shows you is the final frequency used to drive the motor. Maybe this one is better because it shows you the crystal frequency and what each stage would divide down to to get the final motor frequency.

B100 frequency division for motor drive.JPG

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JohnR725 Distinguished Member

JohnR725

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Out of curiosity would you be interested in any other schematics of timing machines? For instance I have the schematic with waveforms for the Bandelin  Tickoprint perfect  T46 Timing machine it looks like it's from the year 1970 at least the schematic the interesting machine with an integrated circuit or two but a complete transistor dividing circuitry

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LittleWatchShop Distinguished Member

LittleWatchShop

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2 hours ago, JohnR725 said:

Out of curiosity would you be interested in any other schematics of timing machines? For instance I have the schematic with waveforms for the Bandelin  Tickoprint perfect  T46 Timing machine it looks like it's from the year 1970 at least the schematic the interesting machine with an integrated circuit or two but a complete transistor dividing circuitry

Would love to!!!!!

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LittleWatchShop Distinguished Member

LittleWatchShop

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8 hours ago, JohnR725 said:

Rather than just the schematic yet the entire manual. Complete with it's very interesting interpretation a waveforms at the very back the schematics.

Very nice!  The Tickoprint operates on the same principle as the Vibrograf.

Clever way to get a lot of gain at high frequencies with a single opamp stage.  Back then opamps were expensive...today they are essentially free.

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  • 10 months later...
LittleWatchShop Distinguished Member

LittleWatchShop

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13 minutes ago, DavidinSB said:

Hi. It looks like you're simulating the circuit using LTSPice. Did you ever get that simulation to work?  Frequency response curves? I need to determine why the difference in results of my Weishi vs. Vibrograf.

Yes...LTSpice. I can send files if you want to fiddle around...tomorrow.

As I recall, they did work.

I picked up another Vibrograf the other day with microphone. The main unit does not work, but I bought it for the mic

Edited by LittleWatchShop
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