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Slo-Syn TS25-1024 "stepper motor" info?

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  • J Tiers
    replied
    Originally posted by Lew Hartswick View Post
    I suggest JTiers was just born about 50 years too late . :-) Back in the early 50s some of the RADAR sets I worked on used those devices . It's been a bit long for me to remember how and for what but I do remember the the name, as well as synchros and all their variations . :-)
    ...lew... Don't know why this is in bold. ???
    Heh.... how old (or young) do you think I am?

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  • MaxHeadRoom
    replied
    I have seen and used these in the past with no problem, they were originally intended to run at set-fixed speed from the mains frequency, in the past I have seen them used for spooling material where a very accurate RPM has to be maintained requiring no additional feedback.

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  • The Artful Bodger
    replied
    Originally posted by sch View Post
    I have one of these from ~15yrs ago, though mine has a name plate identical to J Tiers name plate except for rotation rate of 72 rpm.
    Motor is a chunky thing about 5-8 lbs and 5" diameter , ~6" long. The circuit to run is similar to Artful Bodgers top circuit and
    using a 50ohm 20 watt or so resistor in series with an AC oil type 7.5 µF cap across the red and black wires. Then 120v ac is
    supplied white to white on motor and black to either red or black to switch rotation direction. Rotation rate is fixed, can't be changed.

    I had the idea of using it for a knee motor but it was way too puny for that.
    These and other devices can be extremely frustrating to have in one's possession. They look like they must have been very expensive when new but they stubbornly refuse to respond to any configuration of circuit, voltage or frequencies that we may offer up to them.

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  • sch
    replied
    I have one of these from ~15yrs ago, with mine having a name plate identical to J Tiers name plate except for rotation rate of 72 rpm.
    Motor is a chunky thing about 5-8 lbs and 5" diameter , ~6" long. The circuit to run is similar to Artful Bodgers "A" circuit and
    using a 50ohm 20 watt or so resistor in series with an AC oil type 7.5 µF cap across the red and black wires. Then 120v ac is
    supplied white to white on motor and black to either red or black to switch rotation direction. Rotation rate is fixed, can't be changed.

    I had the idea of using it for a knee motor but it was way too puny for that.
    Last edited by sch; 08-05-2021, 03:45 PM.

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  • MaxHeadRoom
    replied
    Originally posted by Lew Hartswick View Post
    I suggest JTiers was just born about 50 years too late . :-) Back in the early 50s some of the RADAR sets I worked on used those devices . It's been a bit long for me to remember how and for what but I do remember the the name, as well as synchros and all their variations . :-)
    ...lew... Don't know why this is in bold. ???
    If they were synchro's they are a little different technology, they were popular back then but have been largely replaced by other systems now
    The general physical construction of a synchro is much like that of a 3ph electric motor. The primary winding of the transformer, fixed to the rotor, is excited by an alternating current. Due to electromagnetic induction, this causes currents to flow in three secondary windings fixed at 120 degrees to each other on the stator. The relative magnitudes of the secondary currents are measured and used to determine the angle of the rotor relative to the stator. The secondary currents can also be used to directly drive a receiver synchro that will rotate in sync with the transmitter version, IOW one transmits the other moves in
    'synchronism'
    I still have my course books from 1959!
    Last edited by MaxHeadRoom; 07-30-2021, 10:32 AM.

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  • Lew Hartswick
    replied
    I suggest JTiers was just born about 50 years too late . :-) Back in the early 50s some of the RADAR sets I worked on used those devices . It's been a bit long for me to remember how and for what but I do remember the the name, as well as synchros and all their variations . :-)
    ...lew... Don't know why this is in bold. ???

    Leave a comment:


  • J Tiers
    replied
    Is that stepping or just running?

    I'd say that of course it will "run" if you electronically set up the same phase as with the PSC. Getting it to "step" is a bit different, as there is no inertia helping "pull it through". All combinations so far seem to step it forward a step, then back a half or so. At that point, it does not step forward. It sure will lock up with DC, however.

    The link above from The Artful Bodger is supposed to have a circuit for stepping the 3 wire unit, but unfortunately that illustration is a broken link.

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  • MaxHeadRoom
    replied
    The Slo-Syn manual shows the phase shift capacitor version similar to a typical PSC arrangement, Also 2 phase arrangement where a 2 phase supply with 90deg shift can be used to operate the motor from 0 Hz to approx. 100Hz, to obtain 334 rpm for the TS series.

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  • J Tiers
    replied
    Originally posted by MaxHeadRoom View Post

    It is not a PSC in the general sense of the word and typical application, it is a combination, if you like, that uses stepper motor technology in order to synchronize the stepping rate to the frequency of the supply.
    If you were to dismantle and inspect it before any other information, you would deduce it is a stepper motor. 🤔
    it's too bad that a couple of the relevant illustrations from the link are missing..... I have not yet found a sequence that steps this motor, although the link claims it can be done, and illustrates it with fig 20 which is unfortunately a broken link

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  • MaxHeadRoom
    replied
    Originally posted by J Tiers View Post
    So it would seem. It is actually a "PSC" motor, and nothing to do with a stepper despite what it says at the top of the label.

    .
    It is not a PSC in the general sense of the word and typical application, it is a combination, if you like, that uses stepper motor technology in order to synchronize the stepping rate to the frequency of the supply.
    If you were to dismantle and inspect it before any other information, you would deduce it is a stepper motor. 🤔

    Leave a comment:


  • The Artful Bodger
    replied
    I assume the depiction of batteries in diagram 17 indicates this is a DC configuration and the words tell us that one cycle of the potentiometer section would move the motor just one tooth interval (i.e. 100th of a circle). So this is not a continuously rotating motor but one that steps forwards and backwards according to the voltages produced by the potentiometer thingy.

    I do not have and have never seen anything like the potentiometer arrangement but I do have a variety of Slo-Syn devices and I expect they will still be sitting on their shelf when I am carried out the door for the last time.

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  • J Tiers
    replied
    Originally posted by The Artful Bodger View Post
    You really should read and understand the page I posted.
    the potentiometer plan is really a two phase illustration.

    The writeup is fine, as far as it goes, but it is incomplete. It omits mention of the logic needed for the 3 wire version. I tried a lot of different logical inputs, and none would produce the effect of a stepping motor..

    My conclusion was that I need a bipolar supply, but that is a big nuisance, requiring twice the parts and I have no money in this motor, so no need to "salvage an investment".

    The logic for a type of motor I do not have (the 5 wire motor) is shown. My assumption is that the a' and b' notations for that are achievable in a 3 wire by reversing polarity, which requires 2 supplies, and double the usual number of switching devices, logic outputs, high voltage level shifters, etc. It is not clear that a suitable result cannot be had with a normal 48V supply and a normal large stepper at a lower overall cost than the 240V supply that appears to be needed to get this motor operating in a form of step mode....

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  • The Artful Bodger
    replied
    You really should read and understand the page I posted.

    An insight into operation from both pulsed and sinusoidal power is provided by the arrangement shown in FIG. 17. In essence, the potentiometer constitutes a two-phase generator. One complete revolution of this potentiometer advances the angular position of the rotor by one tooth, in the same way that one cycle from a conventional ac supply would. With a rotor having 100 teeth (two 50-tooth sections), 100 revolutions of the potentiometer would be required for one complete revolution of the motor shaft. The positions of the potentiometer and motor always remain synchronously related—a given angular position of the motor can always be “recaptured” by turning the potentiometer back to its total angular displacement from “start” that previously corresponded to that motor position.
    Last edited by The Artful Bodger; 03-25-2021, 02:12 AM.

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  • J Tiers
    replied
    So it would seem. It is actually a "PSC" motor, and nothing to do with a stepper despite what it says at the top of the label.

    What it looked like originally was a stepper that maybe had such a high inductance that it would not work well at fast pulse rates, accounting for what appeared to be a 60 Hz "pulse rate", but what turns out to be a plain old PSC motor with sine wave input and a run capacitor.

    Booooorrrrrrring....... I got lots of little PSC motors. I admit I have got nothing that is 200 rpm, so maybe it will find a purpose.

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  • The Artful Bodger
    replied
    I think this page describes the animal....http://www.industrial-electronics.com/emct_2e_5i.html

    I have seen aircraft instruments which appear to work on this principle (B, below).

    Last edited by The Artful Bodger; 03-25-2021, 12:17 AM.

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