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IBM International Slave: what sort of pulse?

mxfrank

Registered User
Oct 27, 2011
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I picked up an International slave today. I'm not sure what sort of pulse this requires. It has three wires and two coils. I suspect it requires alternating polarity, but I'm not at all sure how to wire it or what to drive it with.

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ibm clock

Registered User
Sep 5, 2005
241
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Typically those are 24v dc. it receives a pulse once a minute. The cam that is on the clock switches the slave from the B to the A wire. I copied a couple pages out of the Simplex Service Manual that describe the timing from the master to the slave. You can drive it with this. Model 1900W-UNV Modular Clock Winder - Ken's Clock Clinic Just connect the A and B wire together. Connect the tied wire to one side of the clock winder and the C wire to the other side of the clock winder.

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Tim Orr

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Good afternoon, mxfrank!

I've run an identical-appearing clock on three 9v batteries connected in series. You can clip them together using their own clips, and if you're lucky, find a wire hookup clip to go onto that. Need a pulsing device. I've used Bryan Mumford's "Slave Driver" with good results, though Ken Reindel is a friend, and his devices work well too, especially since I believe that Bryan has discontinued the "Slave Driver."

Best regards!

Tim Orr
 

mxfrank

Registered User
Oct 27, 2011
163
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I have a spare Mumford driver. Since I have a bunch of slaves of various types, I may use the driver to run a relay bank capable of delivering the various voltages I'll need.
 

fdew

Registered User
Jul 12, 2007
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If anyone is cheep, and has a old PC laying around you can control any slave clock or even different slaves for about $20
USB Relay Module 4 Channels, for Home Automation - v2
The board comes with software that is easy to use. I quickly created a setup to reverse polarity every 30 sec for a European clock.
Even programing hourly correction for IBM type slaves wouldn't be hard (although I run a number of them and they really don't need correction.
There are cheaper USB relays on Ebay (down to $3.00 or so, but they don't have the nice software.
 

ibm clock

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Sep 5, 2005
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That USB relay looks like something fun to play with. Thanks.

You know which IBM slaves need correction? The ones with the movement with the black plastic cam. Otherwise the older International and later Simpex movements usually always run on time.
 

fdew

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Jul 12, 2007
235
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That USB relay looks like something fun to play with. Thanks.

You know which IBM slaves need correction? The ones with the movement with the black plastic cam. Otherwise the older International and later Simpex movements usually always run on time.
One of my first jobs at Simplex was to go through a large high school and remove and replace every "donut movement I found. We were told never to fix them but replace them on sight.
 

ibm clock

Registered User
Sep 5, 2005
241
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I'm working on restoring an IBM double dial clock. it had donut movements in it. but they have to stay. These are not mounted with the rivets and speed nuts. There are mounting posts stamped out of the clock frame. i cant drop a Simplex impule movement in it if I tried. Oh, and the clock face is held in with a staked brass ring, instead of the snap in ring. and when I got it, it was missing the hands, and glass.. I found two clock with donut movements on ebay for parts donors. The clock frames are not made the same as the early 1950s IBMs or Simplex ones. So, I restoring rather than using the wrong parts, or subing newer Simplex clocks on the double dial frame.

Tony
 

fdew

Registered User
Jul 12, 2007
235
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18
once again products that were not real successful became very collectable. As I recall, they would get gummed up and also the contacts would drag on the plastic cam. Both would probably respond to a good cleaning and lube with high quality oil. I never saw one with a burned out coil or broken parts.

Good luck with yours. It is a collectors item.
 
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