Jerry the old IBMs are loud at the 1 minute mark or if pulsed clunk clunk clunk. Great when you first start them annoying after a bit. But if the cost is $0 have fun and learn. With respect to 60 hz motors you will need real power to drive them nothing a micro can do. Something like 20 watts at some voltage. It all varies from manufacturer to manufacturer. There was something else on the IBM clocks and don't recall. But I think if you sent a inverted pulse the clock would go to the top of the hour or was it that it went backwards. I suspect there is some good information online. Regards Paul. WB8TSL
On Fri, Jan 3, 2020 at 7:05 PM Jerry Hancock <je...@hanler.com> wrote: > Thanks for all the input. My friend Dave has over 300 International Time > Recorder master clocks and who knows how many of the old IBM wall clocks. > The slave clocks take 1 pulse per minute and don’t have second hands so > they won’t work. IBM made a wall clock with a second hand and I didn’t > know until you guys posted that I can drive them with pulses, assuming. So > I’m going to talk Dave out of one of those clocks assuming he has a couple > dozen. I have a feeling some also used a synchronous motor. I didn’t > think about it until now, but I guess I can also use a micro to generate > the 60hz (against my reference) voltage for the synchronous motor. Has > anyone tried that or should I just look for a quartz type only? > > > On Jan 3, 2020, at 2:59 PM, Neville Michie <namic...@gmail.com> wrote: > > > > Hi, > > I saw the discussion on PPS slaves and spent some time thinking about > them. > > I have, of course used $3 quartz wall clocks as slaves, but they are > rather poor quality. > > I remembered that in my collection I had some 40cm dials, probably from > an observatory. > > These are all 24 Hour dials, but they contain two alternate polarity > motor units. One > > for seconds, the other for hours and minutes. I had run them in this > mode years ago, > > they use 24 volts and I had to design a driver, the bi-polar drive being > achieved by a > > series capacitor, which was driven by a unipolar square wave signal from > a GPSDO. > > I also have a 10” “Chloride Gents” slave with an unusual bipolar motor > driving worm gears. > > This is a 12 Hour dial with sweep seconds, driven by a single drive. > > This clock then poses the question, “if it stopped how do you correct > the dial?”. > > There is no clutch and adjusting knob, you cannot touch the hands as the > bezel is fixed, > > so you would either have to: > > (a) set an alarm clock to warn you that the time would be right in a > minutes time to start the clock, > > (b) Try to double drive it with 2 pulses per second for up to 6 hours, > > (c) run it backwards for 6 hours, > > or dismantle the slave, which is a major task and likely to cause damage. > > > > This dilemma explains the use of multiple drives in the slaves. > > > > If anyone wants a 40 cm, 24 hour alternate polarity slave without glass > and probably requiring > > re-bushing of its pivots (which is why, I assume, that they were taken > out of service), I have several, > > for free, but in Sydney. > > > > cheers, Neville Michie > > > >> On 3 Jan 2020, at 05:21, Jerry Hancock <je...@hanler.com> wrote: > >> > >> Hello, > >> > >> I looked around but can’t find a wall clock that would take a 1PPS > input signal to drive the minutes and seconds. I’ve made digital modules > using a lot of different displays but would love to have a large, 14” or so > with a second hand, wall clock that I can drive with 1PPS. The old IBM > clocks, etc I found take a pulse on the minute. I have an old pendulum > clock I can drive with a solenoid but thought I would ask here before going > that route. > >> > >> Signal levels aren’t important. > >> > >> Thanks > >> > >> Jerry > >> > >> > >> _______________________________________________ > >> time-nuts mailing list -- time-nuts@lists.febo.com > >> To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > >> and follow the instructions there. > > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > Jerry Hancock > je...@hanler.com > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.