Author Topic: Frequency meter  (Read 39805 times)

MacGyver

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Re: Frequency meter
« Reply #60 on: March 14, 2009, 09:33:42 PM »
Wow.

Yeah, I'm in the states. And on the Far Coast at that.   :(

I could put a piece like that to good use if it was in my shop!  Sigh...

If it was here now, you'd bet I'd come up with a way to power it.  ;D
Steve

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AdeV73

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Re: Frequency meter
« Reply #61 on: March 14, 2009, 09:45:45 PM »

I want to put all of this onto a boad which then interfaces with some ancient computer equipment I have (a Sharp MZ-80K, Z-80 based computer from the late 1970s - chosen because in computing terms, it's a perfect match for the Lister: Old, reliable, cast iron... ;D). However, as old computers tend to be less reliable than old engines, I'm thinking, I'd like it to output data to an RS232 terminal as well, so I can use a terminal or terminal emulator as a backup.

With a PIC for a controller it should be no big trick to spit out RS232 to that old beastie. Sounds like fun. In a twisted sort of way.....


Well, the main board I want to do as pure logic (with A-D converters as required), so it presents to the Sharp as a bunch of numbers in fixed memory locations. But I'd happily use a PIC for the RS232 output, despite having never used one before.

Twisted.... yeah, that's me :D I like the idea of building something that, despite being "high tech electronics" (for the 1970s, maybe) is actually pretty simple, easy to repair, and uses parts which - in theory at least - should be available more-or-less forever (or can be bought for 2 pennies per piece right now).

Plus, I like to experiment with stuff... and as I'm more or less due a mid-life crisis any year now, I see no reason to delay ;D

Quote

That's one of my favorite parts is board layout.  :)


Yeah, I always enjoyed the board layout too - I just never included any parts other than the chips! Just beginning to figure out why you need pull-up resistors, decoupling capacitors, etc; although I'm still not totally sure why & when you need them in digital circuits... But then, I'm only 2/3rds of the way through chapter 2 of the book - it's still looking at transistors as amplifiers; the digital stuff is at least 15 chapters away yet!

Quote

Wow.

Yeah, I'm in the states. And on the Far Coast at that.   :(

I could put a piece like that to good use if it was in my shop!  Sigh...

If it was here now, you'd bet I'd come up with a way to power it.  ;D


Well... on the bright side, that container quote I got was to the west coast (Long Beach, CA) - the only issue is how many engine's worth of space that beast takes up. I'd gess you could fit 4 or 5 6/1's into the footprint. However, the Micromat isn't crazy heavy like the Lister's; so - thinking laterally - if all the engines sit on the bottom of the container, a wooden framework could be constructed & the Micromat put on top. It'd have to be well secured for a sea passage, but there's nowt to make it impossible...

compig

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Re: Frequency meter
« Reply #62 on: March 14, 2009, 10:05:35 PM »
Sounds like me , I have this strange affliction for collecting old electronic  jun............... , errr , equipment as I can't stand the thought of it being scrapped !!  Still have a couple of 8086 PC's from the first networked computer system we had in our family business , a Siemens Telex machine (remember Telex's ??!!) because it's just way to well made to scrap and loads of old test gear form the days when stuff was possible to service and repair. Just bought a Kepco variable DC lab power supply , from the '70's , 0-36 VDC at  0-30 amps. The thing is built like military equipment and I got it cheap because it turned on but there was no output. I was willing to take the chance on it , turns out it is just missing the programming connector from the back !!  However , although Kepco (an American company) still keeps this part , they have a minimum invoice charge and don't deal direct anyway !! Have to get it working though , this thing can be set up to do anything !! One of my favourite old devices is the Nixie tube , I buy any old test gear using those things , they're just so cool !!
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AdeV73

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Re: Frequency meter
« Reply #63 on: March 14, 2009, 10:14:37 PM »

Sounds like me , I have this strange affliction for collecting old electronic  jun............... , errr , equipment as I can't stand the thought of it being scrapped !! 


Yeah... that sounds familiar! Although I've now managed to bring myself to sell on a lot of the old computer stuff I had, I still have too much (an old CBM 3016 - a PET like machine, with 20MB hard disk, printer.... 2 or 3 of those MZ-80Ks, plus an MZ-80A and MZ-80B. Loads of old Sinclair QLs. A Tatung Einstein. A couple of Amigas, somewhere. I just recently sold a couple of old Hewlett Packard minicomputers (they almost paid for the Listers, and they certainly freed up the space to put the listers in!), now they were real tanks of computers. I still have a pile (and I mean, a pile) of old RS232 dumb terminals... oh, and a couple of Sirius ACT-1's from the mid '80s... hmm.... stop now....

Nixies never did it for me, but I am a complete sucker for anything with analogue gauges on it.... one of the reasons I'm looking forward to the output of this very thread: an analogue frequency gauge, how cool is that??  ;D

lowspeedlife

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Re: Frequency meter
« Reply #64 on: March 14, 2009, 10:33:02 PM »
Does my Atari pong game count in this discussion? ::) ::)

     SR.
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compig

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Re: Frequency meter
« Reply #65 on: March 14, 2009, 10:56:14 PM »


Yeah... that sounds familiar! Although I've now managed to bring myself to sell on a lot of the old computer stuff I had, I still have too much (an old CBM 3016 - a PET like machine, with 20MB hard disk, printer.... 2 or 3 of those MZ-80Ks, plus an MZ-80A and MZ-80B. Loads of old Sinclair QLs. A Tatung Einstein. A couple of Amigas, somewhere. I just recently sold a couple of old Hewlett Packard minicomputers (they almost paid for the Listers, and they certainly freed up the space to put the listers in!), now they were real tanks of computers. I still have a pile (and I mean, a pile) of old RS232 dumb terminals... oh, and a couple of Sirius ACT-1's from the mid '80s... hmm.... stop now....

Nixies never did it for me, but I am a complete sucker for anything with analogue gauges on it.... one of the reasons I'm looking forward to the output of this very thread: an analogue frequency gauge, how cool is that?? ;D

No way !! Our first business computer was a Sirius !!!  LOL !!  Analogue instruments rock , nothing like row's of gauges !!  A favourite thing of mine was to watch sections of movies where there was a lab or 'take over the world' control room being depicted and rip them apart for a total lack of authenticity or realism. The height of tech always seems to be an oscilloscope displaying a 'sine wave' or if they're really ambitious , Lissajous figures  !!
Then there is that irritating habit of making all electronic equipment 'beep' when a button is pressed or or text appears on a screen !!!  Even now , when analogue gauges are ever used in modern labs they still have 11'ty million of them twitching  from zero to full scale at a couple of Hz or so !!
« Last Edit: March 15, 2009, 09:43:35 AM by compig »
DON'T STEAL , THE GOVERNMENT DOESN'T LIKE COMPETITION !!!
Lister A
Onan W3S Genny
Petter A1
Villiers C45 industrial
Continental flat six powerpacket
ANOTHER Lister 6/1 CS SOM , temporarily !!!

MacGyver

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Re: Frequency meter
« Reply #66 on: March 15, 2009, 03:03:35 AM »
Does my Atari pong game count in this discussion? ::) ::)

     SR.

Yeah, it counts. But If you've got an original Atari Pong, I suggest you DON'T take it apart for Lister projects. You've got a collectors item and the wife ain't gonna understand when you dismember it for "that silly generator of yours".
Seriously...
Steve

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AdeV73

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Re: Frequency meter
« Reply #67 on: March 15, 2009, 09:07:00 AM »
Doesn't that rather presume that the wife deosn't see the Pong game as "that silly old box that should have been thrown away years ago"?  ::) ;)

MacGyver

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Re: Frequency meter
« Reply #68 on: March 24, 2009, 03:02:00 PM »
Hey Scott,

I haven't forgotten about this project, I've just been serious busy.
Spring is here, acres of grass to mow, the wife wants a garden, our tenant is complaining about bats in the walls...   ::)

Your meter is still on the "to do" list, it just got nudged down a few slots.
Steve

JKson (PS) 6/1 'roid & ST 7.5

lowspeedlife

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Re: Frequency meter
« Reply #69 on: March 25, 2009, 01:14:14 AM »
This is not a problem, I'm still welding in between cleaning the garage, so I have somewhere to weld, & some odd jobs that have come up, I roofed a porch today. I think that qualifies as an odd job for an electrician :). when ever we can get to it will be just fine. thanks Mac Gyver.


  Scott R
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mike90045

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Re: Frequency meter
« Reply #70 on: March 25, 2009, 07:40:38 PM »
It's the placement of capacitors, external transistors, diodes & resistors which stumps me....

For a slow computer, it's not too critical.  Higher speed stuff, we put the bypass caps right at the IC pins, and "noisy" parts, we run them off their own regulator, to help prevent the spread of noise.

adhall

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Re: Frequency meter
« Reply #71 on: March 26, 2009, 02:49:39 AM »
Here's a circuit diagram for you:

http://freecircuitdiagram.com/2008/09/06/audio-frequency-meter-using-555-ic/

I would use a small step down transformer to provide low voltage AC for the 9 - 12 VDC power supply and also use this as the input to IC1.

A slightly more elegant solution might be to replace IC1 with another 555 (or, more likely, the second half of a 556 dual timer). IC1 is acting as a comparator to "square up" the sine wave signal to provide a sharp, negative going signal to trigger the 555 timer. Here is a circuit for using a 555 to do that function:

http://home.cogeco.ca/~rpaisley4/LM555.html#13

Best regards,
Andy Hall

JKSon 6/1, 5 kW ST Head, 1992 Dodge RAM Cummins 5.9L Turbodiesel, 2001 VW TDI 1.9L Turbodiesel, 2006 Jeep CRD Turbodiesel, Yanmar FX22D Diesel Tractor