A variable resistor than can be changed mechanically.

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46 views

How do I wire these potentiometers?

I'm trying to make this circuit (components in question are R10 and R11). I have two really nice sliders I bought from Science ...
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2answers
42 views

Differentiate Value of Unmarked Potentiometers

I am constructing a signal generator using a kit. Upon soldering it together, I have encountered a problem. The board is marked with two potentiometer slots, identical except for the values named on ...
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1answer
27 views

Volume control with DS1807 digital potentiometer?

I'm making a digital synth for a project and I need to wire in an Arduino-controlled volume circuit. Right now I'm outputting a 0-5V audio signal and cutting it down to a pure AC 0.5V signal with a ...
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2answers
91 views

How to combine 2 potentiometers together?

I have 2 amplifiers and each has its own variable volume pot on them to control the audio volume. How can I wire both of those to a single pot that will work with both?
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3answers
143 views

If a potentiometer is basically a voltage divider, why are they made in different values?

I was taught that rheostats are current based devices, while potentiometers are voltage based. I can see why rhostats come in different values (eg making variable loads of different magnitudes), but ...
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1answer
27 views

Reading Pot w/out ADC or OPAMP

There was a page on the interwebz once, and it had code (and schematic) for reading an RC ciruit (no op-amp or ADC!) where one of the R's was variable-resistor (LDR, pot, etc.). However I can't find ...
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3answers
109 views

120v 1,500w heater: is the temperature control knob most likely a standard potentiometer?

Are the temperature adjustment knobs on most high-power AC (infrared or radiant) heaters just standard potentiometers, the same that would be found in low-power DC devices? I'm asking about the knobs ...
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3answers
49 views

Speed Control for a 12v DC PC Fan for Magnetic Stirrer

I working on mini project to create a magnetic drink stirrer out of an old PC Case Fan. (For those that don't know, a magnetic stirrer is basically a spinning magnet under your glass and a magnetic ...
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2answers
78 views

How to change speed of dc motor using potentiometer?

I want to change the speed of a DC motor(12V,2000RPM) using a pot and operate a table fan(where I've replaced its AC motor with DC).Now the problem is I get a regulated output at o/p of 7812 but not ...
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2answers
23 views

Cermet potentiometer temperature coefficients

I'm engineering a system that is temperature-sensitive, between ~-10-30C. I've moved to using cermet potentiometers because of their sub-200PPM/C temperature coefficients. If I wire such a pot with ...
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2answers
46 views

Hi-Fi Stereo Amplifier gain regulation with potentiometer

This is my first question ever so please don't kill me :) I have built a stereo hi-fi (end) amplifier 2x10W based on a IC TDA2009. I have bought it as a construction (learning) kit ready to solder. ...
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1answer
92 views

What's the usage of this type of biasing?

I'm trying to know What's the usage of this type of biasing BJTs. this is the main schematic. I'm talking about these type of biasing: Another question to me is this type of biasing for ...
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0answers
36 views

Change range of output values of potentiometer

I would like to use a fuel gauge in my car that expects 240 Ohms when the tank is empty and 33 Ohms when full. However, my current fuel sending unit reads 168 Ohms when empty and 34 Ohms when full. ...
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3answers
48 views

Reading a potentiometer with an unknown voltage

I have a potentiometer that ranges from 0-400kΩ. One pole is connected to a supply of unknown voltage (but it's in the neighborhood of 12-14V: it's a vehicle power supply). The other pole is ...
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2answers
106 views

Potentiometer as Voltage regulator 12V to 6 - 12V range

I am new to electrical engineering and I would like to build simple circuit with potentiometer as voltage regulator. I have simple circuit, as you can see in attached picture below. I have ...
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2answers
153 views

How to adjust linear voltage regulator equivalent?

I'm attempting to build a linear voltage supply. (I'm not touching the mains yet.) My first thought was to use an adjustable linear voltage regulator. Unfortunately, I found that linear voltage ...
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0answers
37 views

Automatically control EQ and Volume on audio signal

I am trying to control an audio signal with a microcontroller. I would use digital pots but seeing as I need 250k ohms, 300k ohms, or 500k ohms, at LEAST 256 taps, and volatile memory, there don't ...
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3answers
43 views

How can I evaluate a potentiometer susceptibility to change?

I have a usage case where I would like a potentiometer for controlling the charge going to a lead-acid battery via a IC. It would be susceptible to some (although not extreme) vibration, such people ...
9
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2answers
913 views

Potentiometers, little piece sticks off?

I'm not electronics savvy and am a complete newbie. So I'm in the middle of a project and am trying to stick a potentiometer through an aluminum casing and I placed a 1/16" piece of rubber between the ...
0
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1answer
52 views

Where would be the best spot to put a logarithmic volume control on this TPA3122 audio amp?

I'd like to add a volume control to the following circuit (a 2x15W Class-D Stereo Power Amp Kit). The schematic below is an image clipped from a PDF I found describing it. This'll be being driven ...
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3answers
93 views

Newbie question: How do pots limit current?

From my understanding, a series circuit has a constant current, and when resistance is placed in the circuit it is voltage that changes across the resistors and not current. Potentiometers, from ...
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4answers
90 views

How to convert 10K Pot raw output ADC data to voltage and resistance from arduino uno?

I have a simple and basic question. I am using Arduino uno to read the output from a 10K potentiometer. I understand that Uno uses a 10 bit ADC, therefore it can display outputs from 0 as 0V to 1024 ...
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2answers
111 views

Can a malfunctioning relay in an amp cause or allow a speaker to crackle when turning the vol potentiometer? [closed]

Ok, so this question has several layers, I admit it. I recently acquired a Lepai 2020A+ amp. It is, I believe, the latest version PCB because it has the two relays for speaker protection instead of ...
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1answer
59 views

Why does POT cause current to divert?

I have a pretty basic question. I put this little thing together but I don't understand why the POT is causing this result. When powered, if the POT isn't fully open. LED 1 is bright and LED 2 is ...
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1answer
143 views

Changing potentiometer from a gaming steering wheel

I have Logitech's vibration feedback wheel which has a rotation of 270 degrees. I am considering changing its potentiometer so it can rotate more (900 degrees or 1000 degrees maybe). What ...
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2answers
67 views

Bi-Directional Rheostat/Potentiometer

is there any known type of device will do the following: [I have read the bi-directional potentiomenters posting LINK but I just joined and can not reply to that posting. I am looking for a rotation ...
0
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1answer
89 views

Calculating feedback resistors for op-amp based voltage regulator

I need to design a voltage regulator with an output range of 20-25V. I managed to re-create this ciruit from a course, but I'm stuck on calculating resistor values. These are the formulas I'm given ...
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3answers
71 views

Is it reasonable for a potentiometer to have a minimum of 1.3Ω?

I purchased a 25Ω linear potentiometer, and found that the minimum resistance is 1.3Ω 0.9Ω. I expected that the minimum would be closer to 0Ω. Is this typical? Should I return the potentiometer as ...
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0answers
71 views

How can I add a resistor in parallel to a rheostat while keeping it linear?

I have a 25Ω linear potentiometer wired as a rheostat. I would like a range closer to 5Ω, so I added two 10Ω resistors in parallel. This gives me a range of 0 to 4.16Ω which is just fine, but the ...
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2answers
196 views

Can I use an op-amp in voltage follower configuration as variable voltage power supply?

I see that this works in theory, but I my gut feeling says there is a drawback or caveat of which I'm not aware. Basically what I want to achieve is described best by the circuit diagram below. ...
0
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1answer
42 views

Looking for a high temperature potentiometer [closed]

Does anyone know of any potentiometers that are rated up to 500 degrees F?
0
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1answer
65 views

Dual Dc regulated voltage circuit design

I'm working on my term project which is designing a dual DC regulated voltage that gives a DC voltage between +or-ve 3 to +or-ve 15. I have completed the testing for positive DC output part, but I ...
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0answers
40 views

Rheostat and how ohms affect them

I have a two welding machines with the same problem. The rheostats, Ohmite 1.5Ω, 5.77 amps, are damaged. The replacement cost from manufacturer are $100 each. After searching on ebay I found some ...
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2answers
61 views

How to regulate voltage into two variable outputs?

I'm thinking of building a control voltage generator for a synthesizer. Basically I want to control two pitch control voltages with variable resistors, something like this: R1 needs to control only ...
0
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2answers
53 views

Potentiometer with No Minimum Resistance

I'm looking to create a variable current regulator with the LM317 using 1-turn pots. I know that I am going to need to have a resistance of 1.25 Ohms to have a current of 1A, which I want to be my ...
0
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1answer
149 views

Use Potentiometer to change frequency in FM Radio Transmitter

I know that in most circuits you use a tank circuit consisting of an inductor and variable capacitor in parallel to generate different frequencies like this one. However since most cheap trimmer caps ...
0
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1answer
85 views

DIY Photobooth: LED puck lights potentiometer suggestions

I'm building a Raspberry Pi powered photobooth, and want to add some lighting. I purchased this set of led puck lights, and would love to control their intensity from the Raspberry Pi, instead of the ...
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3answers
91 views

Calculate resistors value in voltage divider

I have the following voltage divider circuit with a potentiomenter, and I need to find the value of the resistors. simulate this circuit – Schematic created using CircuitLab How can I ...
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0answers
78 views

Circuit with “output” resistance as a linear function of “input” resistance

TLDR: How do I make a 6.8kΩ to 20.0kΩ potentiometer look like a 10.5Ω to 19.7kΩ potentiometer when presented with 3.3 volts? I'd like to make a mod for a MIDI controller. Through some probing I ...
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0answers
74 views

Will this potentiometer control this led strip?

So first off I'd just like to say i know absolutely nothing about electronics. I want to add some lights to my computer case, will this work as a dimmer? 500K 1/2W Linear Taper Potentiometer White ...
0
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1answer
139 views

How to offset input voltage of any op amp

There are some op amps that allow nulling of input offset voltage by provding decidcated inputs where, typically, a potentiometer is connected for the offset correction. My question is that if a op ...
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0answers
36 views

Will my potentiometer provide enough amperage for my h bridge?

I am sending pwm requests to my H-bridge from an arduino. Each pwm signal is a precise so I need to have the h bridge drive it by that specific amount. I want to use 5V for the h bridge supply, so i ...
0
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2answers
254 views

How do I use a 5 pin potentiometer?

I have a 5 pin trim pot I desoldered from an old board. I am assuming maybe it is a dual gang poteniometer or something with a common ground pin. Does anyone have any ideas what the actual pinouts ...
4
votes
3answers
210 views

Simple ADC alternative by using a capacitor and digital Arduino pin

I'd like to measure a dozen potentiometers with an Arduino UNO. Unfortunately, the UNO only has 6 analog pins, but it does have about a dozen digital pins. Could I effectively measure an analog value ...
0
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1answer
71 views

DC motor as a generator as a torque limiter?

Is it possible to use a DC motor as a generator to regulate applied mechanical torque? A hypothetical situation: I have a DC motor acting as a generator attached to the ceiling. The motor shaft has ...
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1answer
105 views

Operational amplifier with potentiometer

Given an op-amp circuit with the shown potentiometer. How does one come up with the following gain equation? Also, when the potentiometer is turned up halfway, why is R3 6.12K, instead of 1.12k ...
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4answers
2k views

Do ‘wiperless’ potentiometers exist?

Potentiometers are renowned for wearing out (at least in my experience); the little wiper eventually just wears its contact and nolonger has a firm electrical connection. For an audio device, this can ...
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3answers
183 views

Controlling the power from a 9V battery with a potentiometer

I'm working on a project where I'm powering an LCD screen backlight via a 9V battery. As it is currently, I'm powering the LCD via a 9V battery. This works great, but I'd like to have the ability to ...
3
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3answers
653 views

3 leg potentiometer - what's the 3rd leg for?

In a potentiometer, I often see the 3rd leg connected to ground. I understand exactly what a potentiometer is physically (a wiper along a log or linear resistance), but I don't understand the benefit ...
-1
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1answer
91 views

Do potentiometers exist that include DPDT switches at the limits?

Do potentiometer packages exist that include 2 double-pole double-throw switches, one of which is switched at the lower limit, the other switched at the upper limit? (Preferably with tactile clicks.) ...