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Cynosure
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Joined: Dec 11, 2010 Posts: 966 Location: Toronto, Ontario - Canada
Audio files: 82
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Posted: Thu Nov 10, 2011 7:39 am Post subject:
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Ok. then maybe I will do this - power the sequencer parts of the lunetta using 0V on the Vss instead of -5. Then I can use the 5V option. |
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diablojoy
Joined: Sep 07, 2008 Posts: 809 Location: melbourne australia
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Posted: Fri Nov 11, 2011 1:46 am Post subject:
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yes matthias that does sound right
was just stressing the importance of not exceeding the rail voltages
would really help to know the ccts cynosure is driving
it could be a 4017 based sequencer running on +5/-5 or equally it could be +5 and 0v with the -5v only used elsewhere
Quote: | power the sequencer parts of the lunetta using 0V on the Vss instead of -5. Then I can use the 5V option. |
cynosure if that is possible to do with the particular lunetta sequencer's
it is not a bad option, though i cant imagine the cct was designed with -5v in mind and there not being a good reason for it [dual rail opamps somewhere ? ] otherwise you could go with a small interface to
offset the pulse voltage to the correct level as in matthias's option D
which maybe the better deal and easier
you could try the M2C with the 5v output first and see if it will clock your lunetta as is , I dont think it would harm anything [ guessing here really ]and if that does not work then tack a small interface cct on the front end of the lunetta to offset the level to -5 low to 0v high _________________ In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Fri Nov 11, 2011 2:04 am Post subject:
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Cynosure wrote: | The CMOS chips run on +5/-5, so the logic signal is a total of 10V. |
so Vdd is +5V and Vss is -5V.
however i have to correct myself. the threshold of i.e. CD4017 would be at approx. +2V then. (High Level Input Voltage is 7V for 10V operation according datasheet).
so just be sure to not exceed the +5V on the lunetta's input.
sorry for the confusion. _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source |
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diablojoy
Joined: Sep 07, 2008 Posts: 809 Location: melbourne australia
Audio files: 11
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Posted: Fri Nov 11, 2011 8:24 pm Post subject:
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Quote: | however i have to correct myself. the threshold of i.e. CD4017 would be at approx. +2V then. |
Doh i should have seen that as well
So the M2C should clock the lunetta fine with its outputs set at +5v _________________ In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Sat Nov 12, 2011 7:09 am Post subject:
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cynosure, are you still there? _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source |
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Cynosure
Site Admin
Joined: Dec 11, 2010 Posts: 966 Location: Toronto, Ontario - Canada
Audio files: 82
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Posted: Sat Nov 12, 2011 10:06 am Post subject:
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Sorry - I was entrapped with soldering a wasp filter (your name on the schematic Matthias, so thanks for that one too).
The thing that the clock will actually be triggering is a 4040. I know the MIDI2CLOCK has a divider in it, but i included one in my sequencer too for use when clocking from other lunetta devices. The output of the 4040 then goes to a 4029, which is decoded using a 4514.
Thanks for the info. I don't have the MIDI2CLOCK soldered up yet (working on the synth/sequencer it controls first), but I can easily breadboard a 5/0V clock pulse to test it out. |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Sat Nov 12, 2011 2:33 pm Post subject:
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Cynosure wrote: | ...I can easily breadboard a 5/0V clock pulse to test it out. |
yes, this would be good. i wonder if the 0V is low enough for the CMOS powered by -5V/+5V...
if not you will have to do it the way i recommended: use 0V/10V triggers and move them down to -5V/+5V on the lunetta side. _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source |
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Cynosure
Site Admin
Joined: Dec 11, 2010 Posts: 966 Location: Toronto, Ontario - Canada
Audio files: 82
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Posted: Sun Dec 18, 2011 8:57 am Post subject:
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FYI. Now that the cmos synth is done, I have tested it out with a 40106 clock on breadboard using a 9V battery and a 7805. It clocks the sequencer if I add a capacitor to the +5 clock pulse and don't use the clock to also power an led. Maybe a current issue?
Anyway, it should work with the 5V option on the midi2clock pcb once I get around to soldering that together. At most, i might need to add a cap on the output.
Thanks for the help! _________________ JacobWatters.com |
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