[sdiy] Is this a comparator?

[James Dunn]

I guess Tom is referring to something like the 4016/4066 bilateral 
switches. You could also use something like an MC3340 VCA (small 8 pin 
IC) although they may not be so easy to get hold of.

James

Derek Holzer wrote:
> Heya Tom,
>
> Ok, thought maybe a two-step process. Signal would be audio or 
> control, in this particular (primitive) system, they are both 
> considered equal. If it's choppy, that's just fine, clicks-and-cuts 
> are part of the app. Can you be a bit more specific about the audio 
> switch?
>
> d.
>
> ps... new AudioWeevil07 looking sharp! They all sold yet?
>
> Tom Bugs wrote:
>> Hiya D
>>
>> Yeah, you want a comparator first and then use the output squarewave 
>> of the comparator to open/close an audio switch (4000 series or DG 
>> one for decent bipolar).
>> Depending on the app you may need some hysteresis or smoothing on the 
>> comparator -- are you treating audio or control signals?
>>
>> Rocking'n'best,
>> Tom
>>
>> Derek Holzer wrote:
>>> There's a function I want to implement, but I don't know what to 
>>> call it so I can't start researching the right circuit.
>>>
>>> I'd like to compare an incoming voltage with a reference voltage, 
>>> and only allow the incoming voltage to pass if it's above the 
>>> reference voltage. I do not want to square the signal, I want to 
>>> pass it unaltered so long as it's above the threshold of the 
>>> reference voltage. When the incoming voltage is less than the 
>>> reference, then the reference voltage would be passed (or none at all).
>>>
>>> What is this function called? A comparator? A gate? It's not a logic 
>>> function, since it doesn't deal with square waves. I imagine it's a 
>>> simple op-amp trick...
>>>
>>> thx + best,
>>> d.
>>
>>
>