More Ben Duncan nonsense and self promotion here
Spectral X-Contamination: Problems in Op-Amp Chips | Stereophile.com
Spectral X-Contamination: Problems in Op-Amp Chips | Stereophile.com
Twisted wire Gimmick Capacitor // what capacitance per unit length?
Is there a "standard value" that ham radio enthusiasts and audio circuit designers use, for the capacitance per unit length of a Gimmick Capacitor?
A "Gimmick Capacitor" is just a twisted pair of insulated wires, where the left end of each wire is a capacitor terminal ("plate") and the right end of each wire is unconnected. The wire-to-wire electrostatic coupling means this is a (small valued) capacitor.
Just now I twisted together two plastic insulated AWG22 hookup wires and measured the assembly on several of my LRC meters. It was tightly twisted, 37 centimeters long, and the average measured capacitance value was 29 pF. So that's
How well does this match up against your experience / conventional wisdom ?
Why? Math says my frequency compensation network needs a capacitor whose lower bound is 0.4pF and whose upper bound is 5pF. Sounds like it could be a job for a Gimmick Capacitor and some wire cutters! Attach 9pF gimmick cap, apply electronic test stimulus, observe response on oscilloscope. Cut off 1cm of gimmick capacitor length, observe change in response. Cut off another 1cm of length, observe. Keep doing this till optimum is located. Measure that capacitor: victory.
Is there a "standard value" that ham radio enthusiasts and audio circuit designers use, for the capacitance per unit length of a Gimmick Capacitor?
A "Gimmick Capacitor" is just a twisted pair of insulated wires, where the left end of each wire is a capacitor terminal ("plate") and the right end of each wire is unconnected. The wire-to-wire electrostatic coupling means this is a (small valued) capacitor.
Just now I twisted together two plastic insulated AWG22 hookup wires and measured the assembly on several of my LRC meters. It was tightly twisted, 37 centimeters long, and the average measured capacitance value was 29 pF. So that's
- 78 pF per meter of length
- 2.00 pF per inch of length
How well does this match up against your experience / conventional wisdom ?
Why? Math says my frequency compensation network needs a capacitor whose lower bound is 0.4pF and whose upper bound is 5pF. Sounds like it could be a job for a Gimmick Capacitor and some wire cutters! Attach 9pF gimmick cap, apply electronic test stimulus, observe response on oscilloscope. Cut off 1cm of gimmick capacitor length, observe change in response. Cut off another 1cm of length, observe. Keep doing this till optimum is located. Measure that capacitor: victory.
Did he take his secret to the grave?I posted that on this thread about 2 weeks ago. Keep up in the back
I posted that on this thread about 2 weeks ago. Keep up in the back
I just read it last night. Mind is slipping ya know! But not enough to not recognize the BD stuff do for what it is.
Edit Ahh yes - now I remember, SW commented
What happened to DIYaudio’s log in procedure ?
When visiting a page with my iPhone I have to log in, but despite always having the box checked to stay logged in I have to renew my log in when coming back later on the day.
This is roughly since the last two weeks, before that I stayed logged in forever.
Hans
When visiting a page with my iPhone I have to log in, but despite always having the box checked to stay logged in I have to renew my log in when coming back later on the day.
This is roughly since the last two weeks, before that I stayed logged in forever.
Hans
The login cookiees work fine for me, and there's a separate forum for such things:
https://www.diyaudio.com/forums/forum-problems/
https://www.diyaudio.com/forums/forum-problems/
Hey dudes, this thread is slower than I remembered., so I'm made a new thread for my double inverting chipamp.
ALD's Double Inverted ChipAmp
So long and thanks for all the fish! Dolphins from HGG.
ALD's Double Inverted ChipAmp
So long and thanks for all the fish! Dolphins from HGG.
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