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Post by angelodp on Jan 9, 2010 16:27:55 GMT -5
Hi, please help me with this. The switch is a spdt. on/ off/on I see ..... but with my dyslexia?? 1. .01 p .02 s .05 = .018 2. .01 s .05 = .0082 3. .01 s .05 = .0082
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Post by JohnH on Jan 9, 2010 16:56:07 GMT -5
So this is a part of a circuit in which a switch is used to combine various capacitors, and you are asking about the resulting values.
With the centre switch lug connected up (probably the toggle lever pointing down), the 0.02 is disconnected, and the 0.01 is shunted. so the result is 0.05 microfarad
In centre position, the switch is off, but the signal is going through the 0.05 and the 0.01. The result is 1/(1/0.01) + (1/0.05)) = 0.0083
With switch connected down, the 0.05 is is series with (0.01 and 0.02 in parallel=0.03), the result is 1/(1/0.05) +(1/0.03)) = 0.019
The result is three capacitance values, and they are sensibly spaced being a factor of 2 and a bit between each step
John
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Post by angelodp on Jan 9, 2010 17:15:30 GMT -5
Thanks John, ok so that first position
With the centre switch lug connected up (probably the toggle lever pointing down), the 0.02 is disconnected, and the 0.01 is shunted. so the result is 0.05 microfarad
Can You explain the shunting.
Can the grounding be done as the contact to the chassis on the switch??
Ange
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Post by JohnH on Jan 9, 2010 17:35:50 GMT -5
by shunting I mean the 0.01 cap is shorted out by the switch, ie it acts like a piece of wire, so the only cap acting is the 0.05.
On the grounding - depends - what are you actually doing with this circuit? Is this in a guitar? or in an amp?
John
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Post by angelodp on Jan 9, 2010 17:47:43 GMT -5
in an amp .... I just don't see the shorting. It looks like the current goes through the .01 fn .05
Oh wait of course its a circle.
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Post by wolf on Jan 10, 2010 3:38:12 GMT -5
I figured I'd redraw that to make it a little easier to read:
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