i am confused about the ganged capacitor pinout

[mk16820]

i am confused about how to use ganged capacitor in circuits i.e, which pin should be connected to which terminal .


plz help ......

 

[sky_123]

I think from the capacitor photo that the capacitor center pin corresponds to the common connection between C3A and C3B. The other two
connections can be connected either way round, it doesn't matter for your circuit - i.e. it doesn't matter if
C3A and C3B are accidentally swapped round.

It looks an interesting circuit. Do report back on the results : )

 

[mk16820]

there are two pins at centre of capacitor ,,so how they are connected to the common connection between C3A and C3B....
"i think that first we have to join both centre pins and then connected to the common connection between C3A and C3B"
is my answer right??

 

[sky_123]

Sorry, you're right, hard to see from that photo. Yes, in that case, join the two center pins together, and they become the common connection.

 

[chuckey]

That "common" connection in the centre is actually connected to the spindle, so in that circuit, when you touch the knob on the spindle you will be adding extra capacity across the bottom capacitor. Just use one section of the variable capacitor, WITH THE CENTRE CONTACT earthed, and wire a fixed 68Pf in series with it.
Frank

 

[sky_123]

Ah, good points! : ) Been a while since I used a variable cap. Memories of frequency drift come flooding back...