Use an simplex impulse wall clock as a regular wall clock - Page 1
Forum section: electronics / projects

author: electrofix
author_rank: Contributor
timestamp: December 23, 2024, 02:56:41 pm
content: I have a simplex 6310-9075 that I want to use as a normal clock. Currently it is an impulse clock that can receive signals for correction from an impulse system. I do not have the impulse system. All I have is a 24vdc transformer which is the voltage it requires. How would I connect it to bypass the "impulse" system and use it as a regular wall clock? Here are some pictures:

author: themadhippy
author_rank: Super Contributor
timestamp: December 23, 2024, 03:06:25 pm
content: tryhttps://www.eevblog.com/forum/repair/use-an-simplex-impulse-clock-as-a-regular-wall-clock/msg5755147/#msg5755147o thats you asking the same ting only 3 days ago

author: xvr
author_rank: Frequent Contributor
timestamp: December 23, 2024, 03:26:39 pm
content: Simple answer - no way.More verbose - this clock moves clock hands by external pulses. You can supply 24V to them, but if there is no input impulses - no moves (this clock do not have any internal timing sources to move hands on its own)You can build external pulse source quite easily, this is not a rocket science

author: SteveThackery
author_rank: Super Contributor
timestamp: December 23, 2024, 03:58:05 pm
content: You need to build your own electronic pulse generator. I have converted a pulse clock to a regular clock using an 8-pin PIC chip. It requires 3 x 1.5V batteries in series and runs for a couple of years before needing new batteries.Now, two important things. Firstly, you need to check what voltage the stepper clock actually needs in order to step. I have an advantage because my clock works on a 220mA current, rather than a particular voltage. Even so, I was able to adjust the stepper mechanism to operate reliably on much less current. If your clock really does need a higher voltage than batteries can easily provide, then you'll need to find a plug-top power supply of the necessary voltage and run the clock from the mains. Most of my electric clock collection run off "wall wart" power supplies between 5V and 24V.I'm not familiar with your particular clock, but some require alternating polarity pulses. This is no problem and easy to provide using a little microcontroller such as an 8-pin (or even 6-pin) PIC.Let us know how you get on.

author: Simon
author_rank: Unknown
timestamp: December 23, 2024, 06:56:32 pm
content: Looking at the photos this does not look like a "regular" clock. There is no driving motor, it's that coil that uses a ratchet mechanism to advance the clock.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: December 23, 2024, 08:29:47 pm
content: Quote from: electrofix link=topic=448521.msg57As above, you cannot 'bypass' anything. You need to provide the impulse power, carefully timed.The photos show a significant solenoid that kicks the ratchet wheel, and quite a few parts on the PCB so it likely needs 24V for enough time to charge the large cap, then the 3 transistors will pulse drive the solenoid to advance the mechanism one click. It will be quite noisy.It looks to have a microswitch that senses 'zero' on the mechanism.Addit: Seems some clocks used 3 wires, as a crude correction. 59 pulses on minutes then it waited for a pulse on 60th wire for hours, with fancier pulse trains possible.That was mainly for large systems where clocks may not always be in-sync, and gave the janitor time to manually prepare all clocks to correct hour, and minutes were managed by the pulses.https://forums.ni.com/t5/DIY-LabVIEW-Crew-Documents/Synchronizing-Dad-s-Antique-Impulse-Clocks-using-LabVIEW-FPGA/ta-p/3517147For just one, you can likely use 2 wire mode.

author: SteveThackery
author_rank: Super Contributor
timestamp: December 23, 2024, 08:32:29 pm
content: Quote from: Simon on December 23, 2024, 06:56:32 pmYes, we've established that. It's a "stepper clock" or "impulse clock". Used widely throughout industrial and commercial enterprises from the turn of the 20th century to the 1970s or so, they were driven from an electric master clock. There were various competing systems: IBM, Pulsynetic, Synchronome and others, some very sophisticated, others less so. These slave clocks are interesting to collectors. Some use a solenoid and ratchet mechanism, and are noisy. Others use what is effectively a two-pole stepper motor and alternating polarity impulses for almost silent operation.I'm afraid I'm not familiar the Simplex system - there weren't that many here in the UK.As I said in my previous post, the way forward is to build an electronic pulse generator and mount in the back of the clock. I use a PIC 12F-something-or-other (can't remember exactly without looking).

author: rstofer
author_rank: Super Contributor
timestamp: December 23, 2024, 08:44:33 pm
content: Make sure you understand how the impulse system provides for automatic hour and minute correction to synchronize with the master clock. There is some info on the web...

author: SteveThackery
author_rank: Super Contributor
timestamp: December 23, 2024, 09:03:27 pm
content: Quote from: rstofer on December 23, 2024, 08:44:33 pmHmmm... that's probably only important if the OP wants to set it up with a master clock. He seems to imply that this clock will operate as a stand-alone device. In that case he can forget all that stuff and just make a device to operate the solenoid once or twice a minute (depending on the original system).Depending on the mechanism, it may well be useful to add a fast-forward feature to allow setting to time.

author: StrayElectrons
author_rank: Contributor
timestamp: December 23, 2024, 10:39:18 pm
content: Luckily, I know about these impulse clocks. From in direction of antique viewpoint which I know this one since I have clock and watch hobbies.This clock have a solenoid kicker that pokes the minute hand once every minute and another circuits using contacts on the clock to impulse the clock to correct time when reset to new time. I remember that back in late 70's once when I caught in the action of clock resetting to new time in action when I was little at dorm I was living in, for deaf and blind school which is large institution so all the clocks were run this way from central master clock. Note this institution still exist to the day.Cheers,

author: electrofix
author_rank: Contributor
timestamp: December 24, 2024, 07:06:40 pm
content: Thank you everyone for your contribution. I will post the updates. I think I have a PIC12F675 somewhere. Just have to figure out now the circuit and how to program it to send the impulse every second and the hour impulse every hour.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: December 24, 2024, 07:58:53 pm
content: Quote from: electrofix on December 24, 2024, 07:06:40 pmWith an impulse driver part that large, practical battery operation is probably out of the question.The simplest driver could be a logic level power MOFET and a surge resistor, to protect the MOSFET from that 470uF cap.Anything with a crystal should be ok for this - MHz xtals are more stable than bare 32kHz units & TCXO are better still, but rare on ready to go modules.The Pi PICO are around the lowest cost modules with a crystal.You can calibrate out any ppm initial offsets using a GPS 1ppsAliexpress have some relay-timer modules with 32kHz crystals, but it's not clear they can do short minute pulses as shipped. They target time-of-day setpoints.

author: SteveThackery
author_rank: Super Contributor
timestamp: December 25, 2024, 12:01:37 am
content: Quote from: electrofix on December 24, 2024, 07:06:40 pmI don't think you'll need any of that. I think it uses a one minute pulse, not a one second pulse, and I think the one hour pulse is only for resynchronisation of clocks that have got out of step.Looking at the photo I can see a partially hidden gear wheel which looks like it is probably part of a traditional "motion work" (ie the 12:1 gearing between the hour and minute hands). I am almost certain that if you apply a one minute impulse to the solenoid the clock will just work and the hour and minute hands will stay in the right relationship.I would approach this by stripping out the PCB and any other bits and bobs and just reducing it to a solenoid. I don't agree with@electrofixwhen he says the impulse driver (what is that?) looks too large. The size of it doesn't necessarily relate to the power required; it's easier to make efficient magnetic circuits if the parts are of decent size. Obviously I might be wrong about that; the only proper approach is to strip it down to the solenoid and then just try it. How much voltage and current is actually required to operate the solenoid?The main reason for a clock not being suitable for batteries isn't the power required, it's the voltage. If that solenoid really does need 24V to actuate, then batteries are out of the question - a pack of sixteen AA cells would be ridiculous!I think@electrofixhasn't properly read and absorbed some of the posts in this thread - certainly not mine! Please, don't over think it. All you need is a solenoid, ratchet, and gearing between the minute and hour hands. All the rest is obsolete because its only of use when the clock is controlled remotely.So, strip it down to the solenoid, and then test the solenoid to see what voltage it actually requires. This is far simpler than you seem to imagine. I've explained this already, but apparently I need to explain it again.When you've done that, and found out how much voltage and current the solenoid needs, please report back and we can move on to the next stage.

author: Konkedout
author_rank: Frequent Contributor
timestamp: December 25, 2024, 12:12:26 am
content: Why not eliminate all of the electrical stuff and drive the clock with a V8 turbodiesel? You could have the most powerful clock in the world. By supplying only 30 gallons of fuel daily and carefully monitoring the tachometer, you could probably get accuracy better than 1 hour per day!!

author: Ian.M
author_rank: Super Contributor
timestamp: December 25, 2024, 02:28:47 am
content: That's a $500 clock so gutting it just because you cant be assed to figure out the driver circuit would be *stupid*. Worst case, leave all the driver board in place, disconnect the yellow wire nuts and tap in to the coil there, labelling the wires in case you need to revert.However it would be preferable to build an impulse generator that simply plugs into its Molex connector. The required pulse patterns to drive Simplex two and three wire clocks are documented on pages 4 & 5 of:http://www.ats-usa.com/pdf_apnotes/MCMODES.pdfI understand the on time of each pulse is typically half a second.You'll need a MCU board, with either an accurate crystal clock*, or a RTC, a dumb H-bridge to output the 24V pulses and a 24V supply (though it may work at lower supply voltages down to about 12V. As the clock only draws about 30mA using a small boost converter to get the 24V from a lower voltage is quite practical. Battery operation is less practical - this mechanism isn't optimised for low energy so years of runtime from one or AA cells just isn't going to happen even if you are an expert at minimising MCU power consumption.Personally I'd pick a WiFi capable MCU board and use a battery backed RTC module with it. That lets you do NTP time correction, + log the time to battery backed SRAM so you can recover from power failures by fast stepping the clock. You can also do daylight saving time correction by stopping for one hour or sending 60 fast pulses after midnight on the appropriate dates.Here's an article about driving impulse clocks with an Arduino:https://www.sound-au.com/clocks/arduino.html* Most Arduinos and clones use a ceramic resonator, not a crystal, for their main MCU which just isn't accurate or stable enough for timekeeping applications. Even if you calibrate out the initial error, drift with temperature is high enough you'll need either a RTC module or daily correction.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: December 25, 2024, 05:09:57 am
content: Quote from: electrofix on December 24, 2024, 07:06:40 pmFor just one clock, you do not really need the master correction methods.You could take the microswitch signal, and feed that back into your MCU, so you can confirm the minute movement (and can correct it as needed)The specs linked suggests this mechanism can comfortably advance at 0.5Hz (1sec on 1sec off), which gives a starting point for manual setting.

author: SteveThackery
author_rank: Super Contributor
timestamp: December 25, 2024, 12:38:48 pm
content: Quote from: Ian.M on December 25, 2024, 02:28:47 am$500 for a Simple slave clock. Wow, that's mad!!Yes, follow the principle of what I've said, but leave all the hardware in situ. Just disconnect it. All you need are the two wires coming from the solenoid - then you can drive it with a little PIC circuit. But please tell us how much voltage and current the solenoid actually requires.EDIT: I might need to eat humble pie! I've been reading up on the Simplex clocks, and it seems that several very different systems exist under the Simplex banner. Some had synchronous motors to provide a continuous drive to the time display, and now I'm wondering if this is the case with the OP's clock. If so, making it stand-alone would be very much simpler than making a pulse generator - just a suitable AC supply. We probably need more detail.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: December 25, 2024, 06:43:43 pm
content: The images in #1 clearly show an impulse solenoid and a microswitch and state 24VDC 35mA, so it is not a sync motor.Web info suggests 2 second & 1 second pulses, but bare solenoids data show they can travel in low 10’s ms.A solenoid is current acting, so the OP could experiment with shorter current regulated pulses to make this less noisy, and tolerant of temperature and voltage changes.With the microswitch as feedback, and a MCU you could even self-train this for least waste energy and noise.

author: Ian.M
author_rank: Super Contributor
timestamp: December 25, 2024, 07:16:12 pm
content: Quote from: SteveThackery on December 25, 2024, 12:38:48 pmNo such joy - its definitely an impulse clock not a synchronous one.https://www.lifesafetycom.com/wp-content/uploads/2018/07/Simplex-6310-9075-impluse-clock.pdf