Hi. I was wondering about pickup winding. which end off the coil windings go to ground (start of windings or end), and what is the beast way to wind pickup (clockwise or counter clockwise.) What is the difference between a pot and a variable resistor? And does it matter which terminal you use when you wire them?
Thanks for reading
General pu winding/wiring questions.
Moderator: jingle_jangle
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mortivan
I can help with the pot's questions.
A pot (potentiometer) has 3 connections: the left side of the resistance, the right side of the resistance, and the wiper. Most pot's used in muical instruments are "audio taper" meaning that the resistive material in the pot is not linear; that is, the resistance from lug 1 to the wiper on an audio taper pot with its wiper exactly centered is much less than the resistance from lug 3 to the wiper. The resistive material increases in resistance logarithmically. This is because we percieve sound volume logarithmically. A linear pot would seem to work only work within a small sweep leaving the rest of the wiper/knob movement useless.
A variable resistor classically has two terminals whose resistance changes as the wiper/knob turns. Virtually all uses for "variable resistors" today are covered by using a pot with either one end lug disconnected, or tied to the wiper lug.
Think of a potentiometer as having it's outside lugs usually connected between ground and a full signal. The wiper provides the signal to the next part of the circuit. No matter where you move the wiper, the resistance (impedance) presented to the previous part of the circuit remains constant (providing the next part of the circuit has a relatively high impedance).
With a "variable resistor" hook-up, the resistance/impedance presented to the previous part of the circuit changes in relation to the wiper. Not good for power/volume applications. Actually, unless all input/output impedances are known, for audio signal purposes you rarely see a variable resistor hook-up. Ric uses them for the "mysterious 5th knob" in some guitars as a blend control I think.
Switching the connections to the end lugs on a pot in an audio circuit results in a "backwards" control with a reverse audio taper - not a very effective control.
Wah-wah pedals usually use "linear taper" pots because the movement is not primarily changing volume, but frequency sweep.
Hope that made sense and wasn't too off topic.
A pot (potentiometer) has 3 connections: the left side of the resistance, the right side of the resistance, and the wiper. Most pot's used in muical instruments are "audio taper" meaning that the resistive material in the pot is not linear; that is, the resistance from lug 1 to the wiper on an audio taper pot with its wiper exactly centered is much less than the resistance from lug 3 to the wiper. The resistive material increases in resistance logarithmically. This is because we percieve sound volume logarithmically. A linear pot would seem to work only work within a small sweep leaving the rest of the wiper/knob movement useless.
A variable resistor classically has two terminals whose resistance changes as the wiper/knob turns. Virtually all uses for "variable resistors" today are covered by using a pot with either one end lug disconnected, or tied to the wiper lug.
Think of a potentiometer as having it's outside lugs usually connected between ground and a full signal. The wiper provides the signal to the next part of the circuit. No matter where you move the wiper, the resistance (impedance) presented to the previous part of the circuit remains constant (providing the next part of the circuit has a relatively high impedance).
With a "variable resistor" hook-up, the resistance/impedance presented to the previous part of the circuit changes in relation to the wiper. Not good for power/volume applications. Actually, unless all input/output impedances are known, for audio signal purposes you rarely see a variable resistor hook-up. Ric uses them for the "mysterious 5th knob" in some guitars as a blend control I think.
Switching the connections to the end lugs on a pot in an audio circuit results in a "backwards" control with a reverse audio taper - not a very effective control.
Wah-wah pedals usually use "linear taper" pots because the movement is not primarily changing volume, but frequency sweep.
Hope that made sense and wasn't too off topic.