Automatic time constant

[xazrules]

Hi, let's assume we have this control voltage, R1, C1 are typical, BUT what if we want to make R2 proportionally variable in respect to the input signal?
i try to explain better, i'd like C2 and R2 to be "automatic", the bigger the input (so the control voltage), the smaller and smaller R2 has to become, slowing down the entire CV proportionally.
With small input signals i'd like them to be completely out of the circuit, becoming a single time constant instead of double.
Is it possible to build something similar?
Many Thanks

 

[Migs 31]

Hi, let's assume we have this control voltage, R1, C1 are typical, BUT what if we want to make R2 proportionally variable in respect to the input signal?
i try to explain better, i'd like C2 and R2 to be "automatic", the bigger the input (so the control voltage), the smaller and smaller R2 has to become, slowing down the entire CV proportionally.
With small input signals i'd like them to be completely out of the circuit, becoming a single time constant instead of double.
Is it possible to build something similar?
Many Thanks

Hi there Xaz,

I don't know if I understood your question correctly, but if you want R2 to get smaller and smaller in Ω - with bigger input - maybe a Vactrol in place of R2 could do that job: with small or no input the R = 1 or 10MΩ and as the signal increases into the Vactrol the R can be = 20K, 10K, 800Ω, 200Ω etc (all depending on the model). I hope I got your question right (maybe not).

M

 

[xazrules]

It seems perfect, I’ll try to experiment with it for sure, thanks Migs!