Synchro/Servo? Stepper? What?
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I want to build something, basically an analog clock where, when power is interrupted, the clock stops. But then, when power is restored, the clock zips around to the correct time. Back in my SATCOM days, the az/el motors would follow the back-in-the-controlroom position controls, but wouldn't move if no power was applied to them. Then slew around to the correct position when the power was turned on. So, basically, like that, in principle. I have no idea what I'd need to get this to work these days. A digitally-controlled analog clock is probably the simplest...if I can figure out how to do it. Suggestions?
We won't sit down. We won't shut up. We won't go quietly away. YouTube, and My Mu[sic], Films and Windows Programs, etc. and FB
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I want to build something, basically an analog clock where, when power is interrupted, the clock stops. But then, when power is restored, the clock zips around to the correct time. Back in my SATCOM days, the az/el motors would follow the back-in-the-controlroom position controls, but wouldn't move if no power was applied to them. Then slew around to the correct position when the power was turned on. So, basically, like that, in principle. I have no idea what I'd need to get this to work these days. A digitally-controlled analog clock is probably the simplest...if I can figure out how to do it. Suggestions?
We won't sit down. We won't shut up. We won't go quietly away. YouTube, and My Mu[sic], Films and Windows Programs, etc. and FB
A Stepper motor[^] is your friend.
Mircea
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A Stepper motor[^] is your friend.
Mircea
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I want to build something, basically an analog clock where, when power is interrupted, the clock stops. But then, when power is restored, the clock zips around to the correct time. Back in my SATCOM days, the az/el motors would follow the back-in-the-controlroom position controls, but wouldn't move if no power was applied to them. Then slew around to the correct position when the power was turned on. So, basically, like that, in principle. I have no idea what I'd need to get this to work these days. A digitally-controlled analog clock is probably the simplest...if I can figure out how to do it. Suggestions?
We won't sit down. We won't shut up. We won't go quietly away. YouTube, and My Mu[sic], Films and Windows Programs, etc. and FB
So if you have a digital battery backed 'clock' keeping time, you could feed out to a couple of octal counters for the hour, six decades counters for the minutes. The time is read from from the counters and translated to a signal for the clock motor, if the power is lost the clock face just stops. Once the power is back up the signal will be a series of steps on from when power was lost the counters 'jump' to the correct time, the hands are not so will spin as fast as they can to show the right time. I think the issue will be getting the correct ammount and style of counters. This is sort of silly thing I enjoy give me chance I'll have a think.
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I want to build something, basically an analog clock where, when power is interrupted, the clock stops. But then, when power is restored, the clock zips around to the correct time. Back in my SATCOM days, the az/el motors would follow the back-in-the-controlroom position controls, but wouldn't move if no power was applied to them. Then slew around to the correct position when the power was turned on. So, basically, like that, in principle. I have no idea what I'd need to get this to work these days. A digitally-controlled analog clock is probably the simplest...if I can figure out how to do it. Suggestions?
We won't sit down. We won't shut up. We won't go quietly away. YouTube, and My Mu[sic], Films and Windows Programs, etc. and FB
If you plan the clock for the Central European market, you are within the coverage of DCF77[^] - it reaches half way up Norway. The DFC77 signals, at 77.5 kHz (really longwave!) are so primitive, both at the physical modulation level and the data format, that I often refer to them as 'Morse code Mark II'. The frequency is so low that you could probably sample the signal from the antenna directly (after a simple tuning circuit) using any standard microprocessor that can take an analog input. (My PC sound card is capable of producing 192 kHz sample rate sound, sufficient for generating the right on-the-air waveforms. I have jokingly suggested that once I get myself a new stereo amp capable of handling analog 192 kHz, I will plug an antenna into the speaker connectors and have my PC generate DCF77 signals to adjust all the DCF77 clocks in my neighborhood by an hour or two :-).) The DCF77 data gives you exact time and date directly in binary format. The simpler way to do it is to feed these digital values directly to a numeric LED display. If you very much want an analog clock, you would use a stepper motor (moving arms 6 degrees/pulse) that at reset moves the arms to 00:00:00, and then moves each arm as many steps as the digital time value indicates. After a power down, you would have to do a reset (which may cause each arm to move all the way around - in theory almost twice: One to go from 1 to 00, and then from 00 to 59, if the arms were at 01:01:01 and the correct time is 11:59:59), but you need not worry about anything else to keep it in sync. If you have battery backup for the stepper motors and the (very simple) electronics - it is as if the smallest Arduino is overkill - the clock doesn't have to stop, unless you want it to. One of my DCF77 clocks says in the documentation that to save battery power, it turns on the receiver once an hour checking for drifts of the internal oscillator, possibly holding back one pulse or giving one extra to the seconds arm, but even the cheapest oscillators nowadays are so stable that hourly check is probably overkill. You can just turn off the receiver completely if external power goes out. I haven't been using a soldering iron for years, so I never build a DCF77 clock like this (but I have come as far as to buy the stepper motors for it :-)) - I guess you know how to handle the electronics much better than I can.
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I want to build something, basically an analog clock where, when power is interrupted, the clock stops. But then, when power is restored, the clock zips around to the correct time. Back in my SATCOM days, the az/el motors would follow the back-in-the-controlroom position controls, but wouldn't move if no power was applied to them. Then slew around to the correct position when the power was turned on. So, basically, like that, in principle. I have no idea what I'd need to get this to work these days. A digitally-controlled analog clock is probably the simplest...if I can figure out how to do it. Suggestions?
We won't sit down. We won't shut up. We won't go quietly away. YouTube, and My Mu[sic], Films and Windows Programs, etc. and FB
You might be able to use an Arduino or better yet, an ESP32 to control the steppers on the thing An IoT Smart Clock Using an ESP32 Development Board[^] IoT Smart Clock using the Mega 2560+WiFi R3[^] These clocks use WiFi and NTP rather than a radio based sync mechanism so they don't support time zones but could be made to be configurable or modified to use the radio system. Anyway, some of the principles therein might be useful. Get an ESP32 as they are cheaper and more capable than arduinos + smaller. I included both for the sake of completeness although the arduino one uses an ESP8266 as it's primary worker CPU, not the ATmega2560
Real programmers use butterflies
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I want to build something, basically an analog clock where, when power is interrupted, the clock stops. But then, when power is restored, the clock zips around to the correct time. Back in my SATCOM days, the az/el motors would follow the back-in-the-controlroom position controls, but wouldn't move if no power was applied to them. Then slew around to the correct position when the power was turned on. So, basically, like that, in principle. I have no idea what I'd need to get this to work these days. A digitally-controlled analog clock is probably the simplest...if I can figure out how to do it. Suggestions?
We won't sit down. We won't shut up. We won't go quietly away. YouTube, and My Mu[sic], Films and Windows Programs, etc. and FB
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I want to build something, basically an analog clock where, when power is interrupted, the clock stops. But then, when power is restored, the clock zips around to the correct time. Back in my SATCOM days, the az/el motors would follow the back-in-the-controlroom position controls, but wouldn't move if no power was applied to them. Then slew around to the correct position when the power was turned on. So, basically, like that, in principle. I have no idea what I'd need to get this to work these days. A digitally-controlled analog clock is probably the simplest...if I can figure out how to do it. Suggestions?
We won't sit down. We won't shut up. We won't go quietly away. YouTube, and My Mu[sic], Films and Windows Programs, etc. and FB
Going from simple to complex: Asynchronous motors with a good reduction and an external encoder can work. Steppers will do it if you don't need much torque and you don't need them to rotate fast (they can loose position feedback if they turn too fast) (you would need an external encoder to prevent that). Servomotors will give you a bigger range of speeds and torque while not suffering from the loss of precision at fast speeds. :beer:
www.robotecnik.com[^] - robots, CNC and PLC programming
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If you plan the clock for the Central European market, you are within the coverage of DCF77[^] - it reaches half way up Norway. The DFC77 signals, at 77.5 kHz (really longwave!) are so primitive, both at the physical modulation level and the data format, that I often refer to them as 'Morse code Mark II'. The frequency is so low that you could probably sample the signal from the antenna directly (after a simple tuning circuit) using any standard microprocessor that can take an analog input. (My PC sound card is capable of producing 192 kHz sample rate sound, sufficient for generating the right on-the-air waveforms. I have jokingly suggested that once I get myself a new stereo amp capable of handling analog 192 kHz, I will plug an antenna into the speaker connectors and have my PC generate DCF77 signals to adjust all the DCF77 clocks in my neighborhood by an hour or two :-).) The DCF77 data gives you exact time and date directly in binary format. The simpler way to do it is to feed these digital values directly to a numeric LED display. If you very much want an analog clock, you would use a stepper motor (moving arms 6 degrees/pulse) that at reset moves the arms to 00:00:00, and then moves each arm as many steps as the digital time value indicates. After a power down, you would have to do a reset (which may cause each arm to move all the way around - in theory almost twice: One to go from 1 to 00, and then from 00 to 59, if the arms were at 01:01:01 and the correct time is 11:59:59), but you need not worry about anything else to keep it in sync. If you have battery backup for the stepper motors and the (very simple) electronics - it is as if the smallest Arduino is overkill - the clock doesn't have to stop, unless you want it to. One of my DCF77 clocks says in the documentation that to save battery power, it turns on the receiver once an hour checking for drifts of the internal oscillator, possibly holding back one pulse or giving one extra to the seconds arm, but even the cheapest oscillators nowadays are so stable that hourly check is probably overkill. You can just turn off the receiver completely if external power goes out. I haven't been using a soldering iron for years, so I never build a DCF77 clock like this (but I have come as far as to buy the stepper motors for it :-)) - I guess you know how to handle the electronics much better than I can.
:omg: Never even considered that. Even though I'm old and am used to things like LORAN-C (we used it just for the pulses, not positioning).
We won't sit down. We won't shut up. We won't go quietly away. YouTube, and My Mu[sic], Films and Windows Programs, etc. and FB
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So if you have a digital battery backed 'clock' keeping time, you could feed out to a couple of octal counters for the hour, six decades counters for the minutes. The time is read from from the counters and translated to a signal for the clock motor, if the power is lost the clock face just stops. Once the power is back up the signal will be a series of steps on from when power was lost the counters 'jump' to the correct time, the hands are not so will spin as fast as they can to show the right time. I think the issue will be getting the correct ammount and style of counters. This is sort of silly thing I enjoy give me chance I'll have a think.
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You might be able to use an Arduino or better yet, an ESP32 to control the steppers on the thing An IoT Smart Clock Using an ESP32 Development Board[^] IoT Smart Clock using the Mega 2560+WiFi R3[^] These clocks use WiFi and NTP rather than a radio based sync mechanism so they don't support time zones but could be made to be configurable or modified to use the radio system. Anyway, some of the principles therein might be useful. Get an ESP32 as they are cheaper and more capable than arduinos + smaller. I included both for the sake of completeness although the arduino one uses an ESP8266 as it's primary worker CPU, not the ATmega2560
Real programmers use butterflies
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That sounds simplest, so far. :)
We won't sit down. We won't shut up. We won't go quietly away. YouTube, and My Mu[sic], Films and Windows Programs, etc. and FB
It is my task in life to find the simple way to do things! Engineers are essance lazy, they find generally find a simple cheap way of doing things, managment complicate :-D
