Cool, so inversion in the attenuverter is inverting around the 0V mark, while inversion via logic is inverting the signal in absolute terms.ColinP wrote: ↑Wed Oct 20, 2021 1:54 pmYou don't need a DC offset. It's just pure Boolean logic.huggermugger wrote: ↑Wed Oct 20, 2021 1:17 pmCool, this works as well as the other. But can you explain how this patch creates the DC offset that martb''s solution requires?
The NAND gate (like the NOR) gate has functional completeness. You can construct an entire computer with just NAND gates.
Gate invertor
- huggermugger
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Re: Gate invertor
- huggermugger
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Re: Gate invertor
The NAND approach is simpler, just one module and voilà! On the other hand, the DC + attenuverter approach is easier on my brain, feels more 'hands-on' if you know what I mean. That said, I do a lot of generative-type patching, and it'd benefit me to get more comfortable with the logic module.
Re: Gate invertor
Absolute in Boolean algebraic terms, exactly.huggermugger wrote: ↑Wed Oct 20, 2021 3:21 pm Cool, so inversion in the attenuverter is inverting around the 0V mark, while inversion via logic is inverting the signal in absolute terms.
Logical inversion (NOT) turns true into false and false into true.
A NAND gate performs Q = NOT ( A AND B )
If A and B are both the same then we can ignore B and it becomes simply..
Q = NOT A
And in the world of VM, false = zero volts and true = five volts.
Re: Gate invertor
Yeah, martb's solution is using real number algebra instead. It's calculating...huggermugger wrote: ↑Wed Oct 20, 2021 3:34 pm
The NAND approach is simpler, just one module and voilà! On the other hand, the DC + attenuverter approach is easier on my brain, feels more 'hands-on' if you know what I mean. That said, I do a lot of generative-type patching, and it'd benefit me to get more comfortable with the logic module.
x = - ( gate - 5 )
So if gate = 0
x = - ( 0 - 5 ) = 5
And if gate = 5
x = - ( 5 - 5 ) = 0
Both approaches are equally valid. But if you are used to working with an analog computer (which is what a voltage controlled synthesizer effectively is) then the real number algebraic method makes more sense.
- honki-bobo
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Re: Gate invertor
Inversion with the Attenuverter is the same as multiplying your signal with -1.huggermugger wrote: ↑Wed Oct 20, 2021 3:21 pm Cool, so inversion in the attenuverter is inverting around the 0V mark, while inversion via logic is inverting the signal in absolute terms.
The Boolean Logic module interprets a signal as "high", if it is greater than or equal to 2.5 V, else it is "low". That's why NAND works for inverting gate signals.