Author Topic: Gus Smalley's NPN vero - capacitor question  (Read 2042 times)

jonboper

Gus Smalley's NPN vero - capacitor question
« on: February 11, 2017, 09:49:11 AM »
I'm in the middle of the beginner build, new to circuits and soldering. From the schematic it doesn't look like polarity matters in regard to any of the capacitors.

http://www.aronnelson.com/gallery/main.php/v/French+connection/Vero+Layout/NPN_Boost.jpg.html

I have two questions about the potentiometer and the capacitor (C4) on it.

1. I read in another post that the capacitor on the potentiometer should always have the negative lead on the outer lug. Is that true in this case?

2. I read in the forum that the capacitor is connected to lugs 2 and 3 in this boost, which would mean that the pot in the schematic is being viewed from the top, but potentiometers are typically pictured from the bottom. I'm confused about this...

duck_arse

Re: Gus Smalley's NPN vero - capacitor question
« Reply #1 on: February 11, 2017, 10:15:09 AM »
hello and welcome, jon.

the 3 pinkish caps on the layout are all polarised. the greyish mark on each corresponds to the (-) leg of each. this is the conventional way to indicate the direction of aluminium electros, whatever colours you choose to use. [with tantalums, the (+) is usually marked instead.]

as for the pot, it is shown from the back (otherwise, there would be a representation of the shaft drawn in), so the top terminal, "1" is the hot/CW terminal. C4 (+) connects to the wiper or C or "2" terminal, and the cap (-) to the CCW/cold/3 lug and ground. 1, 2 + 3 can lead to confusion, whereas the counterclockwise lug is always found in the same place.

cap C1 has no polarity.
"I think we're done here."

jonboper

Re: Gus Smalley's NPN vero - capacitor question
« Reply #2 on: February 11, 2017, 10:44:44 AM »
Ah, thanks so much for clearing that up for me Stephen. More desoldering practice...

Those polarity indicators sure are subtle! I thought that was just an x-ray effect.