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Scot Solida
Joined: Oct 24, 2009 Posts: 100 Location: Hutchinson Kansas
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Posted: Wed Dec 09, 2009 12:57 pm Post subject:
Weird Clock Divider issue Subject description: odd behavior on outputs 2 + 3 |
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I'm having a strange issue with the Clock Divider... it operates normally when using input/output 1 and output 2. However, output 3 is being affected by the positions of the switches for both 2 and 3. Oddly enough, it only happens if switch 2 is set to a bigger division than switch 3.
It doesn't matter which input I use, I get the same bevavior. Output 2 is only being affected by its own switch (as it should be). Strange... |
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yusynth
Joined: Nov 24, 2005 Posts: 1314 Location: France
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Posted: Thu Dec 10, 2009 6:03 am Post subject:
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Check that D7 and D12 are healthy, supposing one or both are dead (short-cut) this could explain the behaviour. Check also for solder bridges on you PCB (and if you etched the PCB yourself) check there no microscopic shortcut (tiny copper thread) between tracks. _________________ Yves |
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Scot Solida
Joined: Oct 24, 2009 Posts: 100 Location: Hutchinson Kansas
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Posted: Thu Dec 10, 2009 6:27 am Post subject:
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Thanks Yves! I'll take a look this morning (after coffee ). I did indeed etch the board, so that may be it, too... I'll get out the magnifying glass... |
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Scot Solida
Joined: Oct 24, 2009 Posts: 100 Location: Hutchinson Kansas
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Posted: Sat Dec 19, 2009 11:09 am Post subject:
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I finally got this working properly this morning. Only thing is, I am not entirely sure how I got it working. I rewired the whole thing, tidying it up with molex connectors and ribbon cables. However, that wasn't the problem. I then went through and resoldered most of the joints, checked for shorts. It worked for a few minutes, but when I installed it into the modular, it went back to the old behavior. Weird. So I took it out, pushed on the (socketed) chips, straightened up a couple of caps that had leads bent precariously closely to the diodes and tried again. It worked perfectly. I reinstalled it into the modular and it is still working. I have no idea what was wrong. I may re-build it from the ground up with a neater PCB (this was my first home-etched board, done one the same day as the immediately successful Minimoog filter PCB).
I wish I knew the answer, but I'm happy with the module now that it's working properly. It's just what I needed with my three modular sequencers (and a fourth when I get the Klee built). |
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yusynth
Joined: Nov 24, 2005 Posts: 1314 Location: France
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Posted: Sat Dec 19, 2009 12:14 pm Post subject:
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Weird indeed, I have a question : what brand of 4017 are you using ? ... _________________ Yves |
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Scot Solida
Joined: Oct 24, 2009 Posts: 100 Location: Hutchinson Kansas
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Posted: Sat Dec 19, 2009 12:44 pm Post subject:
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I tried a few of them... I think I ended up with an NTE and a couple of others that look like they have the Texas Instruments logo on them (I had these lying around). Might have been an STE, though, I have some of those too.
I should re-address what it was doing. At first, i thought switch 2 was over-riding channel 3, but in actuality, it was adding to it whenever switch 2 was set to a slower clock division. So if switch 2 was set to 1/4 and switch three to 1/2, the output would be the length of both added together, if you see what I mean. |
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