How to change a capacitor's capacitance...?

Question

How can I make a variable capacitor?

Answer 1

Here is the most easy way to make a variable capacitor with thing that you can find at home. Find two metal cans,one is small than the other one. The small one can be put in freely into the big one. Now put a layer of tape covers totally outside the small one. Tape acts the insulation between two cans. Solder one wire to outside of bigger can,also solder one wire to inside of smaller can. Placing the small can inside the bigger can,by moving in or out the smaller can,you make a variable capacitor. You can test its capacitance with a capacitor tester.

Answer 2

For large values, connect them in parallel in a 1:2:4:8 series using DIP switches. Then set the switches as appropriate. You could also use relays controlled by a knob and a microprocessor.

Answer 3

Either change the distance between plates or adjust the ammount adjacent plates overlap.

Answer 4

you can buy them, but only for small values in the 100 pF range.



reference has some.



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