Pot schematic symbol

[frets]

Hi Guys,

I’ve been steadily working on pedal circuits. I ran across a schematic with a pot symbol that I’ve never seen before. In other words, it’s not the typical pot symbol. I have it below circled in blue. What has me confused are the two arrows. As always, thank you for the clarification.

[tubejockey]

The arrows show which way is "up", or clockwise.

[unreg]

Hmmm… that rectangle in your blue circle looks like a 10K resistor to me. Do they even make 10K guitar pot? The pickups would have much treble with a 10K pot.

Especially with a 10K tone pot…

“Listen I got new 10K pots in my guitar!”
“Ok…”
“(loud sound from guitar with both pots at 10)”
“…”
“Those trains that pass by our house every minute; can’t hear them… and I can’t even hear myself anymore.”


Obviously, I haven’t a clue to what I’m talking about. Are the pot symbols just the vertical solid arrow?

[newey]

Nov 22, 2022 23:41:15 GMT -5 unreg said:

that rectangle in your blue circle looks like a 10K resistor to me.

A pot is a variable resistor, that's why the symbol looks like the symbol for a resistor. You can tell it's not a resistor but is a pot because it has the center wiper connection, shown as the arrow pointing into the rectangle of the resistor. tubejockey is correct, the arrow pointing upward designates the direction of rotation to clockwise.

There are certainly 10K pots, and you might well find one in a guitar with active circuitry (i.e., an onboard preamp). But wiring one into a passive guitar would not make it louder, it would take away all the treble.

You are thinking of this in terms of "Less resistance = more output" which is too simplistic, you have to think about the circuit as a whole, including the amplifier. Good old Ohm's Law: V = I x R, where "V" is voltage, "R" is resistance (in Ohms) and "I" is the current (in amperes). You have to "do the maths" as they say.

Another way to think of this is in terms of an "overwound" or "hot" pickup. These have more windings in the coil, and thus have higher resistance. But the increased number of turns of wire means more current is induced as well, and the output from such a pickup is higher notwithstanding that it has a higher resistance.

[Deleted]

It's not really needed as its just used the potentiometer as a variable resister

It's the UK icon for resister , US being the zig zag

Also in my last Electric course it's U=IR
(I don't make this stuff up, I just put them in your head and force them) Have A Nice Day Now

[sumgai]

Nov 24, 2022 16:25:09 GMT -5 @angellahash said:

Also in my last Electric course it's U=IR

That'd've been a course in German.  The Germans consider "U" to be a force, measured in Volts, which uses V for it's units.

There is a slight disparity in how terms are used in formulas like this.  In English, we tend to simplify.  In German, and I assume it's possible in other languages, the terms are more differentiated, to be more closely correct.   "E" stands for Electromotive Force, the directly translation for the German word Spannung.  The Germans make that distinction in normal speech, we don't.  (Well, I do. I still say "E = I * R, just like I learned it in school.)

And the coup d'grace is the letter "U" was chosen simply to distinguish it from the letter "v", which was already taken.  In English, this makes no sense at all, but in other languages, they take it in stride, and look at us askance, as if we were a bit daft.  (And remember, so far we've been using the Roman alphabet. How do you suppose this simple formula translates to Arabic?  The Cyrillic alphabet?  Or an oriental language?  Hah! made you blanche!  )

Just for grins, and because I'm a real bugger of a so-and-so, I'll let it drop that Ohm's Law also translates into the realms of Physics¹, Chemistry, Thermodynamics, Acoustic Science(!), and other disciplines that are well above my pay grade.  The results come out in different terms as appropriate, but it's the same 3-factor equation.  And often it's called Ohm's Law.   What a world we live in, eh?

HTH




sumgai

1.  In point of fact, Georg Ohm was a physicist, a member of the Royal Society, and a teacher of physics.  He originally expressed the formula in terms common the the physics discipline.  It wasn't for several years that as the study of electricity advanced that the formula was rewritten to better favor that field.

[Deleted]

I am English , and it was a electricians course so Maybe its Europe that is asking for U.

American English Maybe different.

[sumgai]

Nov 25, 2022 6:03:25 GMT -5 @angellahash said:

I am English , and it was the electricians course so Maybe its Europe that is asking for U.

American English Maybe different.

True right there, both sentences.

I'm not up on how closely the British folks adhere to the SI conventions and standards, but "U" is the official designator for what I call "electromotive force". "U" was chosen because choosing "S" for Spannung would easily have led to confusion with the lower-case "s" used almost universally for seconds (of time).





sumgai

[unreg]

Nov 26, 2022 15:10:44 GMT -5 sumgai said:

"U" was chosen because choosing "S" for Spannung would easily have led to confusion with the lower-case "s" used almost universally for seconds (of time).





sumgai

and obviously, with the lower-case “s” used universally for sumgai (of gn2).