At the elementary school that I went to in the 60's, they used Stromberg-Carlson clocks with the sync feature. I remember them at 59 minutes would pulse several times, even if they were correct, but would not advance until the 60th (0 time) minute. I also remember when they were slow, they would step up to the 59th minute where the minute hand would "lock" but still pulse. They were pulse driven though and would receive a step pulse every minute that lasted about 5 seconds. I knew the master was in the front office, but really didn't know how the system worked. Thank you for the detailed explanation!
Thank you for sharing your memories of the school clock system. I also have fond memories of the synchronized time system at my school and never gave it thought about how brilliant the system was and is. It was fun to learn the intricacies and I was happy to share what I learned. Alan
This is fantastic. I am possibly acquiring a rare IBM master - slave system from the 1940s that was in a commercial application, and there is no documentation on it. One of the mysteries was how the time correction works. This really helps!
Thank you Alan for making this video. I worked on a beautiful International Master Clock with the 2 vial mercury pendulum for a friend who’s father worked for IBM before he passed. In return my friend gave me a Simplex Radio Time master clock with an invar pendulum. He said Simplex bought out the time division of IBM. Thanks again for the video.
Thanks Alan. I bought an ITR Master off Les with the dual jar mercurial pendulum. It keeps excellent time. I had no idea how their correction systems worked. You made it very easy to understand. Your collection is awesome.
I remember our clocks in high school had a similar correction system... the clock in the music room, for whatever reason, would always stop at exactly 10:32 AM. At 10:59, however, it would advance to the correct time and continue.
Hi Matt, Can't explain the music room clock but leave it to IBM to correct it every day. Thanks for sharing a memory from the good old days. Happy New Year!!
Great explanation! I got an IBM clock recently, so was kinda wondering why it was using 3 wires at first, altho managed to figure out that it must be some kind of auto-correction feature. Turns out I was right, altho it turns out to be a lot more advanced that I thought. Don't have an IBM master to run this unfortunately, and the Siemens master I use doesn't have that feature so glad to find this video and see it in action. Keep up the good work :)
Sorry I missed your comment. I am happy that it helped explain the extra wire. The correction feature is beautiful. Keep looking for an IBM master clock.
This was fascinating, thanks for sharing. Growing up I've moved around a whole lot and been to a whole bunch of different schools. (about 13) I remember a number of them still using these (I graduated high school in 07.) I even remember the mercury pendulum master clocks often in the administrative office and the slaves clicking every minute.
I worked has a time recorder service Engineer over 40 years ago and worked on these 3 wire hourly correction systems I still have one here at home not running but 8n storage happy memories
Hi Martin, I think you were lucky to have worked on IBM products at a time when service was more important than just throw out and replace. Thanks for taking time to comment. Happ[y Holidays.
Very good explanation of the inner workings for this IBM master clock. At the end you show a diagram of the leads and switches, do you have that as a file available?
Yes if the clock is more than 10 minutes ahead it will be corrected to the minute but will be at least 1 hour ahead. If behind more that 15 or 16 minutes the hour will be wrong. IBM was very careful to state the ranges of fast or slow corrections. Still it is quite amazing considering it was developed almost 100 years ago.
Can you do a video on IBM Master clocks that use weights and 7-Day automatic winding. And I'd like to know whether you have any Mercury pendulums on any of your clocks
@@SelfWindingClocks my grandfather was a clock collector and had a IBM Master Clock that was approximately 5 ft tall in a wooden case that had a long pendulum with two vessels of mercury on it and when I was about 16 years old my grandfather was getting ill with cancer and he sold the clock because he didn't want any of us to have to bother with it. and it was my favorite clock I didn't say anything to him when he went to sell it because , I didn't want to bother him with it that, I wanted it and if you had one like that I would very much love to hear the motor kick in and wind the weights up I know that sounds really corny
Brilliant description Alan. Question; if a system had a mix of 60 beat and 120 beat secondaries, how might that system differ from this basic design, if indeed it differed at all?
Hi Patrick, IBM secondaries have minute impulse movements. IBM did have master clocks with 60, 80, 72 and 120 beat movements that could have had correction systems. Self winding clock co. did have 60 and 120 beat clocks that were considered subsidiary (could have been termed secondaries) and were part of their correction system.
Hello Alan, thanks for making a complicated concept understandable. I recently bought an International Time Recording Co. slave...round, very heavy with a cast iron base and a brass dial ring. It has three brass terminals on top marked A, B and C. Not having a master clock, I was thinking of buying an electronic impulser. Could you please tell me which terminals that would connect to? I imagine "C" is common? Thank you. James in Toronto.
Hi James, I am happy that this video helped. Sounds like you found a nice ITR slaver clock. Yes the "C" terminal on the slave clock will be connected to one impulser terminal and the other impulser terminal should be connected to spliced wires from both the "A" and "B" slave clock terminals.
Hello Alan, at this moment I am working in the restoration of an IBM Model 25 Master Clock, used to control a Tower Clock. I wonder if you have a wiring diagrams of the winding circuit, because de magnets are not working when the minute impulse contact is closed. Many thanks
Hi Juan Carlos, There are wiring diagrams on the IBM Archives web site. Look under archives then exhibits then Clock corner. Lots of information. Send me an email address and I can send a simplified wiring diagram.
@@SelfWindingClocks Having problems when writing an addres, but it is bucefalo323 with the g. I would like to send you pictures of other clocks that we are working with at my University, from other manufacturers as Faraday, Stromberg, National and Siemens.
Hi J. Alan Bloore thank you for all the great information i have just brought a IBM Master Clock to restore, i have been looking get one for a long time, if you would like to see the clock it's on here www.flickr.com/photos/182081477@N07/ i did not know how good the IBM Master Clock is, it's an amazing Master Clock and i am looking forward to restoring the clock. Do you have any information on the clock like the plans for the mechanism, i will have to make a new clock suspension spring as it is broken, do you have the dimensions for it please. Regards Peter
Hi Peter, Email me a contact address. I have suspension spring dimensions. Your clock collection is beautiful. The IBM website has lots of good technical information. Alan
@@SelfWindingClocks Hi Alan, thanks for your reply. I have had a look at IBM website it very good thanks, i still need some more information on the clock. Regards Peter
At the elementary school that I went to in the 60's, they used Stromberg-Carlson clocks with the sync feature.
I remember them at 59 minutes would pulse several times, even if they were correct, but would not advance until the 60th (0 time) minute.
I also remember when they were slow, they would step up to the 59th minute where the minute hand would "lock" but still pulse.
They were pulse driven though and would receive a step pulse every minute that lasted about 5 seconds.
I knew the master was in the front office, but really didn't know how the system worked.
Thank you for the detailed explanation!
Thank you for sharing your memories of the school clock system. I also have fond memories of the synchronized time system at my school and never gave it thought about how brilliant the system was and is. It was fun to learn the intricacies and I was happy to share what I learned. Alan
I am 73 years old and I remember clocks like these that advanced the minute hand once each minute when I was in elementary school.
This is fantastic. I am possibly acquiring a rare IBM master - slave system from the 1940s that was in a commercial application, and there is no documentation on it. One of the mysteries was how the time correction works. This really helps!
Wow! An amazing feat of engineering and succinctly explained in < 15 minutes!
Thank you, yes amazing engineering. Appreciate your comment. Alan
Thank you Alan for making this video. I worked on a beautiful International Master Clock with the 2 vial mercury pendulum for a friend who’s father worked for IBM before he passed. In return my friend gave me a Simplex Radio Time master clock with an invar pendulum. He said Simplex bought out the time division of IBM. Thanks again for the video.
Thank you Norm. Sounds like you earned a nice master clock. I like the radio masters.
Thanks Alan. I bought an ITR Master off Les with the dual jar mercurial pendulum. It keeps excellent time. I had no idea how their correction systems worked. You made it very easy to understand. Your collection is awesome.
Sounds like you have a great master clock. I am pleased the correction video was helpful. Very kind of you to let me know it was helpful. Alan
great video, my master and slave have been ticking since 1984
Trying to remember when I got my first IBM master. You have me beat.
I remember our clocks in high school had a similar correction system... the clock in the music room, for whatever reason, would always stop at exactly 10:32 AM. At 10:59, however, it would advance to the correct time and continue.
Hi Matt, Can't explain the music room clock but leave it to IBM to correct it every day. Thanks for sharing a memory from the good old days. Happy New Year!!
Great explanation! I got an IBM clock recently, so was kinda wondering why it was using 3 wires at first, altho managed to figure out that it must be some kind of auto-correction feature. Turns out I was right, altho it turns out to be a lot more advanced that I thought. Don't have an IBM master to run this unfortunately, and the Siemens master I use doesn't have that feature so glad to find this video and see it in action. Keep up the good work :)
Sorry I missed your comment. I am happy that it helped explain the extra wire. The correction feature is beautiful. Keep looking for an IBM master clock.
Great video and explanation! Thanks for the video!
Thank you, hope it helped.
This was fascinating, thanks for sharing.
Growing up I've moved around a whole lot and been to a whole bunch of different schools. (about 13)
I remember a number of them still using these (I graduated high school in 07.)
I even remember the mercury pendulum master clocks often in the administrative office and the slaves clicking every minute.
I love to hear that others remember the the clocks in their schools. Thank you for sharing your memories of these fabulous timekeepers.
Regards, Alan
I worked has a time recorder service Engineer over 40 years ago and worked on these 3 wire hourly correction systems I still have one here at home not running but 8n storage happy memories
Hi Martin, I think you were lucky to have worked on IBM products at a time when service was more important than just throw out and replace. Thanks for taking time to comment. Happ[y Holidays.
Love this, would love to find an old master, I really want one from IBM too :D
Keep looking. They are out there
Very interesting, thanks!
Thank you for watching and taking the time to let me know.
Very good explanation of the inner workings for this IBM master clock.
At the end you show a diagram of the leads and switches, do you have that as a file available?
Hi Harry, Thanks for watching and yes I can send you a file with this diagram. E mail me at jabloore@aol.com and I will send.
It seems to me that a clock that is more than ten minutes ahead or behind would not receive the B signal in a timely fashion. Did I misunderstand?
Yes if the clock is more than 10 minutes ahead it will be corrected to the minute but will be at least 1 hour ahead. If behind more that 15 or 16 minutes the hour will be wrong. IBM was very careful to state the ranges of fast or slow corrections. Still it is quite amazing considering it was developed almost 100 years ago.
Can you do a video on IBM Master clocks that use weights and 7-Day automatic winding. And I'd like to know whether you have any Mercury pendulums on any of your clocks
Hi Nathan, What are you looking to see in a video on weight driven IBM master clocks? Yes some of my clocks have Mercury pendulums.
@@SelfWindingClocks my grandfather was a clock collector and had a IBM Master Clock that was approximately 5 ft tall in a wooden case that had a long pendulum with two vessels of mercury on it and when I was about 16 years old my grandfather was getting ill with cancer and he sold the clock because he didn't want any of us to have to bother with it. and it was my favorite clock I didn't say anything to him when he went to sell it because , I didn't want to bother him with it that, I wanted it and if you had one like that I would very much love to hear the motor kick in and wind the weights up I know that sounds really corny
Hi Nathan, send me an email address that I can send you a video with sound of the IBM weight driven master rewinding. Alan
Brilliant description Alan. Question; if a system had a mix of 60 beat and 120 beat secondaries, how might that system differ from this basic design, if indeed it differed at all?
Hi Patrick, IBM secondaries have minute impulse movements. IBM did have master clocks with 60, 80, 72 and 120 beat movements that could have had correction systems. Self winding clock co. did have 60 and 120 beat clocks that were considered subsidiary (could have been termed secondaries) and were part of their correction system.
Hello Alan, thanks for making a complicated concept understandable. I recently bought an International Time Recording Co. slave...round, very heavy with a cast iron base and a brass dial ring. It has three brass terminals on top marked A, B and C. Not having a master clock, I was thinking of buying an electronic impulser. Could you please tell me which terminals that would connect to? I imagine "C" is common? Thank you. James in Toronto.
Hi James, I am happy that this video helped. Sounds like you found a nice ITR slaver clock. Yes the "C" terminal on the slave clock will be connected to one impulser terminal and the other impulser terminal should be connected to spliced wires from both the "A" and "B" slave clock terminals.
@@SelfWindingClocks Perfect, thanks so much Alan. I'm enjoying your other videos...what a beautiful collection.
@@jamesweekes6726 Thank you James
Amazing! Is your collection ever visible to the public? Thanks
Sometimes. Where are you located?
Hello Alan, at this moment I am working in the restoration of an IBM Model 25 Master Clock, used to control a Tower Clock. I wonder if you have a wiring diagrams of the winding circuit, because de magnets are not working when the minute impulse contact is closed.
Many thanks
Hi Juan Carlos, There are wiring diagrams on the IBM Archives web site. Look under archives then exhibits then Clock corner. Lots of information. Send me an email address and I can send a simplified wiring diagram.
Last one is Siemens not IBM, sorry.
@@SelfWindingClocks Having problems when writing an addres, but it is bucefalo323 with the g. I would like to send you pictures of other clocks that we are working with at my University, from other manufacturers as Faraday, Stromberg, National and Siemens.
@@juancarloscarmona5901 Not sure I can help but send to jabloore@aol.com
Our school slave clocks only got impulses every 2 mins . Is that a feature ?
I am not aware of systems that advanced the hands every two minutes. Certainly sounds possible.
Hi J. Alan Bloore thank you for all the great information i have just brought a IBM Master Clock to restore, i have been looking get one for a long time, if you would like to see the clock it's on here www.flickr.com/photos/182081477@N07/
i did not know how good the IBM Master Clock is, it's an amazing Master Clock and i am looking forward to restoring the clock.
Do you have any information on the clock like the plans for the mechanism, i will have to make a new clock suspension spring as it is broken, do you have the dimensions for it please.
Regards Peter
Hi Peter, Email me a contact address. I have suspension spring dimensions. Your clock collection is beautiful. The IBM website has lots of good technical information. Alan
@@SelfWindingClocks Hi Alan, thanks for your reply.
I have had a look at IBM website it very good thanks, i still need some more information on the clock.
Regards Peter
slave clock:{\displaystyle Q_{\text{next}}=J{\overline {Q}} {\overline {K}}Q}
Thanks for watching. Not sure what :{ } means