A variable resistor than can be changed mechanically.

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2answers
56 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 ...
1
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2answers
20 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 ...
1
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2answers
34 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. ...
0
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1answer
87 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
33 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. ...
0
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0answers
74 views

Digital Potentiometer and Motor Speed Controller [migrated]

I'm trying to get a Chinese 20A DC Motor Speed Controller working with a MCP42100 Digital Potentiometer. The analogue potentiometer supplied was 100kOhm. I have programmed my arduino with the ...
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3answers
44 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 ...
0
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2answers
82 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 ...
2
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2answers
137 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 ...
1
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0answers
129 views

Buy amplifier to amplify analog 0-5V signal to 0-10V [closed]

I realise the title question has already been answered here in one way or another: Amplify 0 - 3.3V DAC signal to 0 - 10V and Scale 30-50mv signal to 0-5v range I don't understand electronics very ...
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0answers
36 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 ...
0
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3answers
42 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
906 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
40 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 ...
0
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3answers
82 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 ...
0
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4answers
70 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 ...
0
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2answers
81 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 ...
0
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1answer
57 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 ...
0
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1answer
107 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 ...
0
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1answer
50 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
85 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 ...
1
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3answers
67 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 ...
0
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0answers
61 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 ...
2
votes
2answers
161 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
38 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
62 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 ...
0
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0answers
36 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 ...
0
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2answers
59 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
52 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
129 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
votes
1answer
75 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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votes
3answers
82 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 ...
0
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0answers
75 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
68 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
106 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 ...
1
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0answers
34 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
211 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
198 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
69 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 ...
-1
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1answer
98 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 ...
19
votes
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 ...
0
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3answers
151 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 ...
2
votes
3answers
556 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
votes
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.) ...
1
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1answer
128 views

Controlling fan speed with a rheostat

I just got a rheostat from radio shack to connect to my homemade stir plate. The rheostat looks like: (from here) My question is, how do I set it up? I want to use it to vary the fan speed. I am ...
0
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1answer
176 views

How to shift resistance range of Linear Potentiometers by X ohms in the Positive or Negative direction?

For example, I have a 10k ohm (linear) Thumbwheel Potentiometer. This POT will produce values from 0 to 10k when reading its resistance. Positive Shift How do I shift resistance range values by X ...
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2answers
114 views

Explanation for super-sensitive loose contact inside potentiometer?

Symptom I have a mixing console, where one 6-pin stereo pot is errartic. When I turn it all the way down I sometimes can still hear the left channel at full volume. Explanation The circuit is a ...
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2answers
61 views

Hooking up an 8x8 LED board

I recently bought this 8x8 LED board from geeetech which came with this datasheet. I'm new to programming so I bought this board to "figure it out" but now I'm running into issues I don't understand. ...
0
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0answers
76 views

Using capacitors to control the speed of a relay loop

Background: In my autoshop class at school we are required to make a circuit that uses relays. When one relay comes on the other one shuts off and it creates a loop in which they switch really ...
1
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1answer
67 views

Could I add a potentiometer to a dremel? [closed]

I bought a cord Dremel a while back for some of my personal projects and it seems to speed up after a minute and the rotary bit I like begins to jump and chips pieces away. I haven't sliced the cord ...