XO controlled 480Hz Oscillator
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From: JosephKK on 4 Feb 2010 00:54 On Tue, 02 Feb 2010 11:56:24 -0600, Tim Wescott <tim(a)seemywebsite.com> wrote: >On Tue, 02 Feb 2010 09:47:50 -0800, Chris wrote: > >>> The simplest way is MCU with external crystal. For 480 Hz output, the >>> crystal is likely to be a multiple of 3 MHz. The 12.0 MHz would be the >>> most common. >> >> Is an MCU the same as a PIC? > >All PICs are MCUs. Not all MCUs are PICs. The top contenders that I >know of are the PIC and the AVR from Atmel. There are probably low pin- >count 8051 derivatives out there, not to mention the '430 from TI. > >Intersil ought to revive the 1802 core, in a 16-pin package surrounded by >all the usual peripherals. I would certainly like to see them again, i liked the architecture, though many did not.
From: JosephKK on 4 Feb 2010 01:01 On Tue, 2 Feb 2010 10:34:22 -0800 (PST), Chris <christopher.maness(a)gmail.com> wrote: >On Feb 2, 9:58 am, Silvar Beitel <silverbee...(a)net1plus.com> wrote: >> On Feb 2, 11:29 am, Chris <christopher.man...(a)gmail.com> wrote: >> >> > What is the simplest way to get 480Hz from a crystal controlled >> > oscillator? Looks like most of the pre-packaged XO's and VCXO, seem >> > to put out much higher frequencies. Would a series of dividers be the >> > best way? >> >> > Thanks, >> > Chris KQ6UP >> >> Would a CD4060B + 7.86432 MHz crystal + 1 resistor (maybe 2) + 2 caps >> running at 12 volts work for you? Output (rail-to-rail square wave) >> from Q14. >> >> -- >> Silvar Beitel > >That sounds pretty easy divide by 2^14. Would that be a custom >crystal, or a standard freq? > >I will be trying to repair a 480Hz standard tuning fork. It is >actually a 960Hz fork that had it's divide by 2 flip flop die. It is >from a 70's vintage piece of equipment. The fork is hermetically >sealed with solder in a can. I try to get in there tonight, and if >the dead part is some obsolete IC or something, I will probably >replace with a crystal and divider to get my 480Hz. A crystal would >be more quiet and stable I believe. Maybe, the many analogous properties between tuning forks and crystals make that a potentially shaky proposition. Consider the old Bouleva accutron watches, about 4 ppm on your wrist, better than chronometer grade of the day, done with a tuning fork. > >Thanks, >Chris KQ6UP
From: MooseFET on 4 Feb 2010 09:52 On Feb 3, 9:54 pm, "JosephKK"<quiettechb...(a)yahoo.com> wrote: > On Tue, 02 Feb 2010 11:56:24 -0600, Tim Wescott <t...(a)seemywebsite.com> wrote: > >On Tue, 02 Feb 2010 09:47:50 -0800, Chris wrote: > > >>> The simplest way is MCU with external crystal. For 480 Hz output, the > >>> crystal is likely to be a multiple of 3 MHz. The 12.0 MHz would be the > >>> most common. > > >> Is an MCU the same as a PIC? > > >All PICs are MCUs. Not all MCUs are PICs. The top contenders that I > >know of are the PIC and the AVR from Atmel. There are probably low pin- > >count 8051 derivatives out there, not to mention the '430 from TI. > > >Intersil ought to revive the 1802 core, in a 16-pin package surrounded by > >all the usual peripherals. > > I would certainly like to see them again, i liked the architecture, though many did not. If you liked the 1802, I assume you also like wacking your thumb with a hammer.
From: bg on 4 Feb 2010 11:21 Chris wrote in message <65679271-8f0a-4cf8-85aa-78ca82b88f19(a)k6g2000prg.googlegroups.com>... On Feb 3, 7:35 pm, ehsjr <eh...(a)nospamverizon.net> wrote: > Chris wrote: > > On Feb 3, 7:15 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My-Web- > > Site.com> wrote: > > >>On Wed, 03 Feb 2010 09:13:12 -0600, Vladimir Vassilevsky > > >><nos...(a)nowhere.com> wrote: > > >>>Jim Thompson wrote: > > >>>>On Wed, 3 Feb 2010 06:15:37 -0800 (PST), George Herold > >>>><ggher...(a)gmail.com> wrote: > > >>>>>On Feb 2, 11:29 am, Chris <christopher.man...(a)gmail.com> wrote: > > >>>>>>What is the simplest way to get 480Hz from a crystal controlled > >>>>>>oscillator? Looks like most of the pre-packaged XO's and VCXO, seem > >>>>>>to put out much higher frequencies. Would a series of dividers be the > >>>>>>best way? > > >>>>>>Thanks, > >>>>>>Chris KQ6UP > > >>>>>OK this is probably a stupid idea. But could you phase lock to the > >>>>>8th harmonic of the 60Hz line frequency? > > >>>>>George H. > > >>>>AC Line is sort of sinusoidal, so 8th harmonic content is probably not > >>>>all that wonderful, but a PLL with a DIV8 as feedback should work > >>>>great... do it all in cheapy CMOS, at low power ;-) > > >>>AC -> XOR gate -> RC -> XOR gate -> RC -> XOR gate > > >>>:))))) > > >>>BTW, I actually used that sort of thing for frequency doubling in one > >>>of the projects... > > >>>VLV > > >>Yep. I've done that sort of thing clear up into the GHz range. > > >> ...Jim Thompson > >>-- > >>| James E.Thompson, CTO | mens | > >>| Analog Innovations, Inc. | et | > >>| Analog/Mixed-Signal ASIC's and Discrete Systems | manus | > >>| Phoenix, Arizona 85048 Skype: Contacts Only | | > >>| Voice:(480)460-2350 Fax: Available upon request | Brass Rat | > >>| E-mail Icon athttp://www.analog-innovations.com| 1962 | > > >>I love to cook with wine. Sometimes I even put it in the food. > > > I called a local custom crystal manufacturer -- $18 for a 7864320 Hz > > Crystal. > > Or spend 40 cents for the 3.93216MHz crystal the MooseFET > recommended. In stock at Digikey. Use Q13 to divide > by 8192. > > Ed > > > The most straight forward approach looks like the CD4060B. > > I found a source $3 for a pack of 25. If you look at Fig. 13 in the > > data sheet for the CD4060B, it shows how to hook the crystal up to the > > chip. All I need is two caps and two resistors. The crystal > > manufacturer said that he would give me the values that I need to > > calculate C1 and C2. I am wondering what value I would need for RC. > > > Thanks, > > Chris KQ6UP Well, I already ordered the crystal. I will keep that in mind. I need to make a 60Hz VCXO in a PLL slaved to a 24Hz pulse. That is for later though. Regards, Chris Maness If your camera's drive motor is sync'd to 60 cycles, then you could extract the 8th harmonic of 60 cycles to end up with 480 hz. There would be some value in having both the deck and camera speed controlled by the same reference frequency (line frequency). For that matter, you could install an alternator or optical disk somewhere on one of the camera's rotating parts to generate 480hz. In the long run, I don't see how you are going to sync the two without time code on the film and the tape. Tape will slip, that's guaranteed, and the error accumulates no matter how accurate the capstan speed
From: Chris on 4 Feb 2010 13:08
On Feb 4, 8:21 am, "bg" <b...(a)nospam.com> wrote: > Chris wrote in message > > <65679271-8f0a-4cf8-85aa-78ca82b88...(a)k6g2000prg.googlegroups.com>... > On Feb 3, 7:35 pm, ehsjr <eh...(a)nospamverizon.net> wrote: > > > > > Chris wrote: > > > On Feb 3, 7:15 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My-Web- > > > Site.com> wrote: > > > >>On Wed, 03 Feb 2010 09:13:12 -0600, Vladimir Vassilevsky > > > >><nos...(a)nowhere.com> wrote: > > > >>>Jim Thompson wrote: > > > >>>>On Wed, 3 Feb 2010 06:15:37 -0800 (PST), George Herold > > >>>><ggher...(a)gmail.com> wrote: > > > >>>>>On Feb 2, 11:29 am, Chris <christopher.man...(a)gmail.com> wrote: > > > >>>>>>What is the simplest way to get 480Hz from a crystal controlled > > >>>>>>oscillator? Looks like most of the pre-packaged XO's and VCXO, seem > > >>>>>>to put out much higher frequencies. Would a series of dividers be > the > > >>>>>>best way? > > > >>>>>>Thanks, > > >>>>>>Chris KQ6UP > > > >>>>>OK this is probably a stupid idea. But could you phase lock to the > > >>>>>8th harmonic of the 60Hz line frequency? > > > >>>>>George H. > > > >>>>AC Line is sort of sinusoidal, so 8th harmonic content is probably not > > >>>>all that wonderful, but a PLL with a DIV8 as feedback should work > > >>>>great... do it all in cheapy CMOS, at low power ;-) > > > >>>AC -> XOR gate -> RC -> XOR gate -> RC -> XOR gate > > > >>>:))))) > > > >>>BTW, I actually used that sort of thing for frequency doubling in one > > >>>of the projects... > > > >>>VLV > > > >>Yep. I've done that sort of thing clear up into the GHz range. > > > >> ...Jim Thompson > > >>-- > > >>| James E.Thompson, CTO | mens | > > >>| Analog Innovations, Inc. | et | > > >>| Analog/Mixed-Signal ASIC's and Discrete Systems | manus | > > >>| Phoenix, Arizona 85048 Skype: Contacts Only | | > > >>| Voice:(480)460-2350 Fax: Available upon request | Brass Rat | > > >>| E-mail Icon athttp://www.analog-innovations.com|1962 | > > > >>I love to cook with wine. Sometimes I even put it in the food. > > > > I called a local custom crystal manufacturer -- $18 for a 7864320 Hz > > > Crystal. > > > Or spend 40 cents for the 3.93216MHz crystal the MooseFET > > recommended. In stock at Digikey. Use Q13 to divide > > by 8192. > > > Ed > > > > The most straight forward approach looks like the CD4060B. > > > I found a source $3 for a pack of 25. If you look at Fig. 13 in the > > > data sheet for the CD4060B, it shows how to hook the crystal up to the > > > chip. All I need is two caps and two resistors. The crystal > > > manufacturer said that he would give me the values that I need to > > > calculate C1 and C2. I am wondering what value I would need for RC. > > > > Thanks, > > > Chris KQ6UP > > Well, I already ordered the crystal. I will keep that in mind. I > need to make a 60Hz VCXO in a PLL slaved to a 24Hz pulse. That is for > later though. > > Regards, > Chris Maness > > If your camera's drive motor is sync'd to 60 cycles, then you could extract > the 8th harmonic of 60 cycles to end up with 480 hz. There would be some > value in having both the deck and camera speed controlled by the same > reference frequency (line frequency). For that matter, you could install an > alternator or optical disk somewhere on one of the camera's rotating parts > to generate 480hz. In the long run, I don't see how you are going to sync > the two without time code on the film and the tape. Tape will slip, that's > guaranteed, and the error accumulates no matter how accurate the capstan > speed Well I didn't want to get into all the nitty gritty of the project. The tape deck is a fullcoat recorder. Fullcoat is perforated tape. Therefore the capstans have sprokets, and the sprockets don't slip (if you threaded it right). The deck has two time references. A 480Hz (a 960Hz fork with a divide by two in the can) tuning fork in a can that is almost impossible to open without destroying it, and a sync line in from the camera. The fork standard is putting out 960Hz. I would imagine the divide by two in the can is fried. There is also a jack for 60Hz pulses with a 12V swing from the camera. The deck contains a three stage binary divider (divide by 8), that provides a 60Hz pulse to a 12VDC-to-120VAC inverter. The inverter drives a 120VAC sync motor at a constant speed. The cameras I intend on using with the deck have a flash sync on the camera (think super 8). This sync closes a switch for 5ms 24 times/s. I plan on making a box or installing a PCB in the deck that can convert these pulses to 60Hz pulses. Since the camera speed is not controlled by a crystal reference the deck will keep speed with the camera. Yes, I do realize that if the camera varies in speed it will produce noticeable fluctuations in audio pitch. However, since my projectors don't sync either, it is better to have the deck be the sync slave. I want to keep the thread on the design topic, but I would be happy to discuss sync issues on the yahoo group: http://movies.groups.yahoo.com/group/syncsound/ Regards, Chris Maness |