Kokusai Accuratick - many questions!

Discussion in 'Electric Horology' started by alanb, Nov 9, 2006.

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  1. alanb

    alanb Registered User

    Nov 26, 2005
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    Sorry if this clock is a bit too modern for this forum, but I hope someone might be able to help!

    I recently bought this clock, an "Accuratick" made by "Kokusai Electric" in an Oxfam shop. It's very large (about 28cm on a side) and heavy:

    http://www.wessex.clara.net/Misc/AccuratickFront.jpg

    My eye was drawn by its smart, bold appearance, but I was very surprised when I turned it over and looked at the movement!

    http://www.wessex.clara.net/Misc/AccuratickBack.jpg

    Now to put it bluntly (bearing in mind any circuit that incorporates capacitors is beyond my understanding), what's going on here?! All I can think of is that this might be a "master" clock for a building full of "slave" clocks - is that right?

    There seem to be various circuit boards inside - in the centre, the movement - is that cylinder above it (top middle) the motor? (if so one of its wires has become disconnected).

    To the right, a power supply board with two transformers and some hefty capacitors. The mains lead from this, which should exit from the bottom of the clock, was snipped off by the Oxfam seller for safety reasons :-(.

    Bottom left, a board with four relays and lots more capacitors. What's that doing?

    Most mysterious is some kind of time-switch in the top left corner, with a knob that can be adjusted on the edge of the case, and a dial that runs from 5:30 to 16:00. Why those times?! Two of the wires leading to this appear to have been deliberately snipped at some point as can be seen in the picture.

    And just below the movement, bottom centre, is a solenoid (?) which seems to change the "spot" (visible on the face) from red to white.

    There are two sockets on the base of the clock; they seem to be designed to take simple metal "banana" plugs (if that's the right term, that is, not jack plugs or anything with more than one contact).

    Anyway, I haven't tried connecting it to the mains yet - thought I might wait for some sage advice first (google turns up nothing for "Accuratick" by the way, and nothing relevant for "Kokusai"). I would be interested to know what this clock is all about and whether I can/should run it as a standard mains clock. If it all sounds too complicated I might discard the current works and pop a battery movement on the back instead!

    Thanks for any help!
     
  2. alanb

    alanb Registered User

    Nov 26, 2005
    32
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    Sorry if this clock is a bit too modern for this forum, but I hope someone might be able to help!

    I recently bought this clock, an "Accuratick" made by "Kokusai Electric" in an Oxfam shop. It's very large (about 28cm on a side) and heavy:

    https://mb.nawcc.org/

    My eye was drawn by its smart, bold appearance, but I was very surprised when I turned it over and looked at the movement!

    https://mb.nawcc.org/

    Now to put it bluntly (bearing in mind any circuit that incorporates capacitors is beyond my understanding), what's going on here?! All I can think of is that this might be a "master" clock for a building full of "slave" clocks - is that right?

    There seem to be various circuit boards inside - in the centre, the movement - is that cylinder above it (top middle) the motor? (if so one of its wires has become disconnected).

    To the right, a power supply board with two transformers and some hefty capacitors. The mains lead from this, which should exit from the bottom of the clock, was snipped off by the Oxfam seller for safety reasons :-(.

    Bottom left, a board with four relays and lots more capacitors. What's that doing?

    Most mysterious is some kind of time-switch in the top left corner, with a knob that can be adjusted on the edge of the case, and a dial that runs from 5:30 to 16:00. Why those times?! Two of the wires leading to this appear to have been deliberately snipped at some point as can be seen in the picture.

    And just below the movement, bottom centre, is a solenoid (?) which seems to change the "spot" (visible on the face) from red to white.

    There are two sockets on the base of the clock; they seem to be designed to take simple metal "banana" plugs (if that's the right term, that is, not jack plugs or anything with more than one contact).

    Anyway, I haven't tried connecting it to the mains yet - thought I might wait for some sage advice first (google turns up nothing for "Accuratick" by the way, and nothing relevant for "Kokusai"). I would be interested to know what this clock is all about and whether I can/should run it as a standard mains clock. If it all sounds too complicated I might discard the current works and pop a battery movement on the back instead!

    Thanks for any help!
     
  3. eskmill

    eskmill Registered User
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    Aug 24, 2000
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    Kokusai is an communications equipment manufacturing and supplying arm of the Hitachi Corporation. (check Google again)

    Your Acuratick clock is odd. It has some characteristics of a master or control clock. Perhaps mastering remote secondary slave dials and could control external annunciators (bells) or other devices under program control.

    Too, it is possible that the clock had some control of communications equipment because it appears that Kokusai was principally into the communications business.
     
  4. Eckmill,
    Help me on this reply if you don't mind.

    When alanb says it has not been hooked to the mains yet. I am familiar with the English term "MAINS" meaning household power which is by the way 220V.
    After blowing the picture up poster size it is my opinion that this clock does not hook directly to the Mains/Household power source. I do not think this is a 220V clock or a 110-120V clock.
    At the power supply board I do see a fuse I would be interested to know the value of the fuse VOLTAGE and AMPS.
    I truly think it is a 12V Twleve volt clock.
    Eckmill and anyone else who would like to expand on this please do so. I very well may stand to be corrected. But in the meantime I would suggest that it not be hooked to the Mains supply until more information is gathered.
    Chas.
     
  5. DC Kelley

    DC Kelley Registered User

    Mar 16, 2006
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    #5 DC Kelley, Nov 9, 2006
    Last edited by a moderator: Dec 7, 2017
    I disagree, but I an unsure as well. The lower of the three labels has "50 c/s" which I would presume is 50hz, suggesting line current. The power supply is too old to be of the modern "switching type" (which today can deal with 110/220 and 50/60 sources), and it seems to have "12VA" (i.e.12 watts) on the primary transformer. The fuse will likely say "250 volts" simply as a std rating, and this is not indicative if the input voltage. If the unit in fact used ~12wats, the fuse may be 0.1 amp slow-blow or so. And finally, the remaining section of cord is "zip line" commonly used to carry wall current.

    What is off to me is I do not see any diodes on this board. The three electrolytic caps suggest there should be at 6~12 diodes here for 3 DC voltage supplies. Perhaps they are on the back side. On the order board, I count 16 smaller electrolytic caps, and perhaps four metal caned transistors (hard to tell). This suggests to me it might be a set of two rather primitive (pre 555 chip) timer circuits, but for what purpose I have no idea.
     
  6. eskmill

    eskmill Registered User
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    Aug 24, 2000
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    Fellow sparkies: take a close look at the upper left of the photo.

    I believe I see an AM radio receiver; small dial 540 to 1600kc and a knob to the left.

    Apparently this is a clock-radio receiver with some kind of tone detectors to control relays for remote controls.

    What a wonder!
     
  7. alanb

    alanb Registered User

    Nov 26, 2005
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    Thanks for all this information! The fuse just says "1A", nothing more, but I've had a closer look at the big transformer - this has three "tags" at the bottom, marked 230V, 240V, 250V; the only one connected is the 240V. There are four tags around the top, these are labelled "0", "100V", "8V" and "1.5A", and all are wired up.

    I don't think there is room for diodes (I admit I'm not sure how big diodes are) on the other side of this board as it is only mounted a couple of millimetres clear of the metal base plate. Would the clock's motor/movement require a DC supply?

    I hadn't thought of the dial (53,6,7,8,10,13,16) showing frequencies rather than times, but I don't quite understand the use for this (unless the two plugs in the base of the clock are for a loudspeaker?)
     
  8. alanb

    alanb Registered User

    Nov 26, 2005
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    Just one other thing - I've looked under the pink plastic cover and what I took to be the motor (the big cylinder at the middle top) is in fact another solenoid that pulls at a lever within the movement. Pulling on this manually seems to affect the position of the hands, but not always in predictable ways!

    The actual motor is sticking out from the base of the pink cover, and tracing back the wires, one of them is soldered to the one of the two tags to which the external power lead is connected, so I assume this means it must be an AC synchronous motor?
     
  9. harold bain

    harold bain Registered User
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    Nov 4, 2002
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    Alanb, very unusual looking clock. The pink cover does have 50cs on it which I would take to be ac current. So it likely is run on mains voltage (but how much is not specified). Are the two units on the right of the pink cover transformers? All the elecronic circuits on this would require a transformer if it ran on mains voltage. But what they are for, I don't know.
    Harold
     
  10. Hi Harold,
    I do see the 50c/s on the pink cover. I take that under that cover is a remote controled timeset solenoid. This may work on the regular mains voltage independent of the clock and AM radio. I just can't see the clock running on direct power for the mains supply. I think an aux. transformer and something else is required to make this thing work as designed. I actually think the 8V tap will work the radio and clock. Its just hard for me to understand that small transformer doing all the work. NOW I AM SPECULATING because this is an unknown clock to me.
    Also as ECKMILL suggests the top left-hand section is an AM radio. This whole assembly looks of early 70's vintage to me.
    I am still wondering about the whole assembly. I am only expressing my thoughts, and on things like this I am more often wrong that right. To me it is a guess. I would like to take a VOM meter and just go through the whole thing.
    Below the radio section bottom left corner are 4 relays. Everytime I look at this section I get totally confused. I also think this clock when running will run with a smooth flow of the second hand just as any electric clock does. But it might just be that the minute hand will jump a complete minute once the second hand reaches the twelve. The reason for this thought, look at the second and the relationship between it and the minute hand in the picture.
    Now I'm really confused!
    Charles
     
  11. alanb

    alanb Registered User

    Nov 26, 2005
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    Here is a picture of the movement under the pink cover, from three angles.

    http://www.wessex.clara.net/Misc/AccuratickMovement.jpg

    I have been manually turning the silver motor with my fingertip and it moves the second and minute hand in a conventional "sweeping" fashion, so it does seem as though this is just a conventional AC synchronous clock... whether it's running directly off the 240V, or possibly off the 100V tab of the transformer, I don't know.

    The huge solenoid above the movement (in the first picture, it pulls that lever that can be seen extending horizontally across the picture), when pulled, moves all three hands to the nearest hour - so if the clock is showing 01:40:45, after the solenoid is pulled, it shows 02:00:00.

    So it would follow (maybe??) that the clock is set on the basis of an hourly radio signal. It's just a thought, but here in the UK several of the BBC radio stations broadcast the Greenwich Time Signal - the "pips" - on the hour. Is there any way the clock could be listening for those and setting itself to the hour when it hears them, or is that idea fanciful?
     
  12. DC Kelley

    DC Kelley Registered User

    Mar 16, 2006
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    Okay here is a bit more of the puzzle. Les tipped me off. If the box is an AM radio receiver (I agree) and the time frame here is early 70's late 60's (by the circuit styles and lack of any ICs I agree) and the boards with the many caps is really a tone filter of some type (again I agree but would like to see some toriods for this time period like you would see in DTMF circuits), then what we most like have here is a non-US version of what predated the Emergency Broadcast System. In the US this was called "CONELRAD" (CONtrol of ELectronic RADiation) and consisted of an alerting trigger tone at 1KHz broadcast on AM stations. It came about from a mandate by Truman in 1951 and you can search on CONELRAD and find more. I do not know if CONELRAD was test operated periodically, but if it was perhaps the red eye was to indicate a test was missed or happening.

    I would not be surprised that someone added to this signaling system to make a time distribution system that same way. I have done the same thing with commercial FM modulation and have a couple of patents from it. Seek out pre-CEN and other European-centric work. I will ping a couple of friends at NAB, BBC, and CEN and see if they are aware of any such system (but keep in mind we were children when this thing was developed).

    I suggest you put 220V from your local mains on it, plug an 8 ohm speaker into the jacks and see what you get. These tones ceased being sent in the 70's, so unless you have a signal generator that can produce the requisite tone on an AM modulation, you may not be able to trigger that part of it. Seek out any local Ham or electronic hobbyist, they may have such equipment for a test.
     
  13. eskmill

    eskmill Registered User
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    Aug 24, 2000
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    I suspect AlanB, that your guess is a good one.

    The transistor/capacitor/inductor circuits of the 1950's could possibly detect the specific tone used with the "six pips." With some clever timing circuits a sequence of six pips could be decoded with the relays to energize the clockworks synchronizing solenoid. Now, fifty or sixty years later, the six pips could be decoded with an integrated circuit on a chip.
     
  14. DC Kelley

    DC Kelley Registered User

    Mar 16, 2006
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    #14 DC Kelley, Nov 11, 2006
    Last edited by a moderator: Dec 7, 2017
    Here is anther web fragment on the use of the red light, excerpted from
    http://www.textfiles.com/digest/TELECOMDIGEST/vol12.iss0751-0800.txt

    Update:
    So of the four relay, we seem to have one for each of..
    <UL TYPE=SQUARE>
    a) Loss of carrier (off the air), red indicator
    b) 1 KHz CONELRAD alert tone, enable speaker drive
    c) Reset to next hour, when &lt;?&gt; tone present\
    d) So what does relay number four do?
    [/list]
    It is not at all fanciful to suggest your clock was meant to do this, it fact it seem increasing probable from the data that this clock was intended as an alerting monitor designed to do that very thing. Find the guy at BBC with some memory of these events and the mystery will be fully solved.
     
  15. skruft

    skruft Registered User
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    I would only suggest being careful about applying 240v, as I think Japanese electrical power is only 100 volts.
     
  16. alanb

    alanb Registered User

    Nov 26, 2005
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    Well I connected power to this clock to-day. The movement works well and is almost completely silent.

    I also reconnected the four broken/snipped wires that I could see.

    Some things I have found - the red/white circle on the front of the clock. This appears to be a "power cut" indicator - the orange electromagnet below the movement holds the metal shutter so that "white" is displayed, but when the power is interrupted the shutter drops to show a red indicator on the face. The magnet is not powerful enough to pull the shutter up again when power is restored - but when the user pulls the knob on the base of the clock to reset the hands, this also pulls the shutter back against the electromagnet, where it sticks until the next power cut.

    There is a switch within the movement that is closed for a few minutes either side of the hour. I believe that this cuts off the power to the receiver and relay board, presumably so that they're not switched on 24 hours a day.

    I was wrong about the sockets in the base of the clock. They take tiny 2.5mm mono jack plugs. They are connected in parallel, but the left hand one breaks a circuit when the plug is inserted, the right hand one doesn't.

    I tried plugging a speaker into one of these but could hear nothing. Tracing back a wire from the the socket, I found it went straight to a 10k Ohm potentiometer (just about visible in the top left corner of the relay board), which obviously seems to be a volume control. Tried altering the level but to no effect. (Question (remember I know nothing of electronics!) - I used a multimeter to measure the impedance across the two outer contacts of this pot (the middle one is not connected to anything) and it showed a constant reading of just over 10k - is this how it should behave - I imagined the reading would vary as I turned it back and forth?)

    Anyway, without being able to hear anything, I tried altering the tuner frequency. This does make one of the relays "chatter" now and again, but other than that there was no reaction and the big solenoid that sets the hands to the hour never fired.

    So I think this is about as far as I can go with the clock, as I am not an electrically-minded person. There is probably a dry joint, or a failed capacitor, or something, that is preventing it from doing whatever it should be doing, but I don't have the knowledge to track it down.

    It's still a nice looking clock though, and after a polish it will take pride of place on my wall (once I've rigged up a power socket for it so I can't see any trailing wires that is!)

    I will write to Kokusai in the hope that they might be able to supply me with some history of the clock, and will post their reply here if it's useful.

    Thanks for all your advice and interest!
     
  17. eskmill

    eskmill Registered User
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    Because the built-in radio receiver is AM type, then it probably has a ferrite loop antenna coil that would normally suffice as an antenna to recieve strong AM broadcast signals from nearby transmitters.

    However, the metal case around the clock, may inhibit the receiver's antenna coil/loopstick function. Look for a conntection to an external antenna.
     
  18. alanb

    alanb Registered User

    Nov 26, 2005
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    I'm not sure it was a reception problem - (although the tuner board (made by Sony!) does indeed have a ferrite rod aerial on the back) - the speaker was just completely silent - no hiss, static, or anything.

    I found a little mention on Kokusai's web site (not picked up by Google earlier because of the spelling):

    1962 KE commercialized the radio-controlled watch, "Acuratic." (It was launched on the market the subsequent year.)

    I am amazed they managed to build a radio controlled watch back then, given the size of this clock.

    Perhaps it was a pocket watch that required specially tailored pockets!
     
  19. I would like to thank everyone,including but not limited to: alanb, les, D C Kelly, Harold and Skruft for their posting on this subject. To say the least this has been a learning experience for me.
    This is the type of technology that I have an intrest in BUT KNOW NOTHING ABOUT. This technology appeared during my childhood and disapeared in the same period. It is the foreunner to our jump into the Space Race, and due to the advancement in technology was obslete almost over night. (I think). I truly did not know this type of clock existed. Without a fourm of this nature this type of technology just disapears.
    alanb, do watch over this clock and do document what you can while you can on this very unusal timepiece.
    Once again thank you for posting the pictures and taking the time to to let us (me) learn from what you have.
    Respectfully,
    Charles
     
  20. alanb

    alanb Registered User

    Nov 26, 2005
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    Just noticed all the pictures in my old message had disappeared after I changed ISP - so here they are again! No new query.

    View attachment 2115
    http://www.sandbourne.eclipse.co.uk/Misc/AccuratickBack.jpg
    View attachment 2116
     
  21. alanb

    alanb Registered User

    Nov 26, 2005
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    Have just received some information about the "Accuratick" from the nice people at Hitachi-Kokusai.

    Unfortunately it's in Japanese :-(

    A picture of what I guess is a different model of Accuratick can be seen, with a girl presumably setting her watch by it. I can see a reference to "NHK" (Japan's state broadcaster) in the text.

    If anyone here happens to speak Japanese and can translate, that'd be great! 27097.jpg 27098.jpg 27099.jpg 27100.jpg
     
  22. alanb

    alanb Registered User

    Nov 26, 2005
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    I found out a little more about these clocks recently.

    "RC-111U" appears to be the model number of my clock. Recently an "RC-101C" was advertised on a Japanese auction site. Dare I say it looks a rather cheaper model than mine...

    RC101C-a.jpg

    The Japanese "UEC Museum of Communications" has an RC-107 as an exhibit (no picture online though). Their pages say:

    Japan's first radio clock was invented at the University of Electro-Communications

    Since humans have a clock, "clocks that accurately tell the time" have been human dreams.

    In the 1960's, a clock that automatically adjusted the time using a time signal of a radio, which was widely used as a means of accurately setting the time at that time, was commercialized. The University of Electro-Communications professor Masashi Kanno has developed a method to receive the time signal of the radio by electronic circuit technology and automatically adjust the hands of the clock, and this was released by Kokusai Electric Co., Ltd., a wireless communication device manufacturer from 1963. It is Japan's first radio clock "Acura-Tech".

    It was installed at the platform of each station on the Keio Line, including the Keio Teito Railway Chofu Station, the nearest station to the University of Electro-Communications, at Seibu and Tobu stations, banks, schools, hotels and hospitals. In addition, it was installed on the roof of a large building in front of the station and caught the eye. A total of about 6000 units were sold.

    The announcement of the development of a radio clock was made in 1962, but it became popular in the industry. At this time, Kokusai Denki Co., Ltd.'s stock price had reached a stop, and the magazine "Living Handbook" contained a "watch to adjust by yourself" (I would like to recommend it) Watch).

    Technically, there were struggles to eliminate malfunctions. At that time, IC technology was in its infancy, and there was a limit to miniaturization, and it could not be applied to wristwatches and clocks. In 1970, quartz clocks using crystal oscillators became mainstream.

    Keio Electric Railway temporarily installed a radio clock on the top inside the front and back of each train car. At that time, Dentsu university students using the Keio line saw this and boasted that it was a clock invented by a teacher at our university.

    On campus, there was a demonstration using actual equipment at a research presentation held in the conference room on the 2nd floor of the main building. And applause. It is a frame of the early days of the school landscape.

    [and on another page:]

    Although the principle is a little different, Dr. Sugano, the owner of the technology of extracting extremely small areas of sound waves and radio waves called filters, distinguished the sound of the noon time signal of NHK and aligned the clock hands to one point around 1950. Was invented by Kokusai Electric, which was in the territory of Japan.
     

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