A variable resistor than can be changed mechanically.

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1answer
37 views

ATMega328p SPI with MCP41100 digital pot

I'm trying to communicate with a MCP41100 over SPI using an ATMega328p and can't seem to get it to work. Here is the code I found, can anybody see what I'm doing wrong? ...
2
votes
4answers
112 views

Potentiometer Puzzle - TIG Pedal

I'm looking at a brand new foot pedal for a Tungsten Inert Gas (TIG) welder. This foot pedal uses cascading potentiometers to send a signal to the welder control system. I'm getting unusual results ...
6
votes
3answers
498 views

Can I do this tutorial without a potentiometer?

I am trying out online tutorial to practice python and Raspberry Pi. I am currently following this tutorial. It says a potentiometer is needed, but I don't have one. The lcd I have is JHD162A What ...
18
votes
6answers
2k views

Why should I use a logarithmic pot for audio applications?

Just got really curious about it reading this answer from Spehro Pefhany. There Spehro comments that one should use a logarithmic pot for audio applications. So I googled for it. The best I could ...
1
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1answer
87 views

Potentiometer not reading ohms

I have a potentiometer for the volume control in my electric guitar. My multimeter reads 485K ohms on a 500K pot putting my test leads on each outside lug, which is fine I believe. When I put a test ...
0
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3answers
73 views

Linear potentiometer for suspension travel

I am working on a project for university measuring the extension of a cars suspension. I have a potentiometer available to me, but have a few questions regarding how to use it. I understand that it ...
0
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1answer
28 views

LM393N with hysteresis and potentiometer

I am having a bit of a problem with this next circuit: The problem is, when there is 0V at the base of Q1 and when the potentiometer is set close to 100 kOhm. Because of the hysteresis set on LM393N, ...
0
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2answers
70 views

Potentiometer Ripple under load

I have the following circuit with a 10k 0.5w trim potentiometer. simulate this circuit – Schematic created using CircuitLab The voltage after the bridge rectifier is maintained at ~8.6 ...
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1answer
48 views

3296 trimpot adjustment

I've got a 3296 trimpot like this one: http://pdf1.alldatasheet.com/datasheet-pdf/view/78495/BOURNS/3296.html I don't know whether clockwise or counter-clockwise increases or decreases the ...
0
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1answer
61 views

Computer-readable potentiometer

I have a device that essentially controlled by a potentiometer and a rotary switch. I would like to keep these (although I would replace them with other components if that helped), but I'd like to be ...
0
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1answer
121 views

Magic smoke released from DIY PSU… but why?

I'm starting to learn what I can about electronics, and recently decided to follow this (and similar) guides to building a bench power supply out of an ATX PSU: ...
3
votes
2answers
165 views

What's the concept of potentiometer?

So here's a picture of a potentiometer from my book. And my book says that the potentiometer is used for measuring internal resistance (of a cell), emf (of a cell) etc. But I cannot understand the ...
0
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1answer
75 views

Is it possible to design this circuit with a single potentiometer (L-pad)?

I'm designing an L-Pad for my speakers. They attenuate the signal while keeping a consistent effective impedance, which is necessary for the amplifier and crossover circuits. Typically, these values ...
6
votes
1answer
217 views

How do I create a knob like on my amplifier

On my amp, I have a big round knob, that I can turn forever in both directions, to control volume. It simply turns up whenever I turn clockwise and down when I turn counter clockwise. There is no ...
1
vote
3answers
176 views

How can I scroll through all colors of an RGB LED using an Arduino microcontroller and a single Potentiometer?

The RGB LED is supposed to be controlled by PWM, how can I map the position of a potentiometer to a color combination?
4
votes
3answers
204 views

Where to get/How to make a potentiometer with “clicking” steps?

Maybe you remember that very old (and sturdy!!!) electrical panels/machines had those big knobs that you could turn to fixed positions (steps) with a very unique clicking sound. I need to make one or ...
1
vote
1answer
51 views

Potentiometer protection circuitry [duplicate]

My question arose from my previous question about a wind direction measuring circuit. Please have a look at the manual: http://www.fondriest.com/pdf/rm_young_05103_manual.pdf And here is the figures ...
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vote
1answer
92 views

Wind direction measuring circuit

I have some difficulty to understand the schematics for the following anemometer: http://www.fondriest.com/pdf/rm_young_05103_manual.pdf I have confusion at 5 points. Here is the schematics: In ...
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votes
2answers
79 views

How do I put in a volume control on this wired phone headphone set?

I have this headset which I use with a cordless handset. The problem is the volume is way too loud even if I turn it down all the way on the cordless handset. There are no controls on the headset. I ...
2
votes
2answers
192 views

Potentiometer Volume Control

Electronics theory newbie here (please be gentle): So I have an old guitar amp that had a crackly volume control. It also had an annoying habit of going from no volume to "too loud" with the ...
8
votes
6answers
262 views

Can this work as an ADC Input setup and is it common?

Would this work? I'm pretty sure in theory it should, but I don't see it often or at all. In theory, the voltage divider from 2:1 to 1:2 should give 3.3v at one end and 1.6v at the other end of the ...
1
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1answer
84 views

Digital potmeter in transimpedance amplifier feedback

I am considering using a digital potmeter with, e.g., I2C interface as the resistor in the feedback loop of my transimpedance amplifier. I am concerned about this. Will this add any additional noise ...
1
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1answer
97 views

How to connect a “touch sense” pin to a analog or digital input

I'm using a motorized fader that has a "touch sense" pin (see this data sheet), which should be able to detect when someone touches the fader. I want to use it to stop the motor and switch from ...
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votes
2answers
390 views

How to use a digital potentiometer to control current

I am attempting to rig an RC Car's rear wheels to an arduino. Initially I attempted to just hook it into the powered digital pins but after MUCH headache I realized I wasn't getting enough current. ...
4
votes
2answers
189 views

Maximum power transfer

I have problems to solve the next exercise about maximum power transfer. I know that potentiometer has two internal resistors. In this exercise, I must find the \$R\$ value to transfer maximum ...
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2answers
105 views

Potentiometer voltage change

I'm trying to understand simple things about electricity reading allaboutcircuits.com web. This chapter includes image which´s principle I don't understand. Here it is: When supplying constant ...
2
votes
2answers
195 views

How can I stablize an analog to digital reading?

I've built a clock out of a PIC16F877, some LEDs and other stuff... To set the time in 5 minute intervals, I'm using a 22K ohm potentiometer connected between GND and +5V with the contact connected ...
2
votes
2answers
173 views

Capacitor in circuit for potentiometer?

In a German tutorial video about EAGLE, starting at 1:15 the author adds a trim potentiometer for regulating the contrast of an A162 display. Between the slider and ground he adds a 100 nF capacitor. ...
3
votes
1answer
174 views

Potentiometer with four pins?

Normally potentiometers have three pins, but the Song Huei's SL-20V has four. According to the datasheet: 1, 2, 2', and 3 What is the fourth pin for? Update Disassembly shows that @jippie's ...
3
votes
3answers
653 views

Potentiometer with LM317

I am trying to make an adjustable power supply with an LM317 and a potentiometer. The only problem was that there were some conflicting schematics online about how to connect everything. Can some ...
0
votes
1answer
212 views

Does anyone have a G pot graph?

How does the G pot (or Graphic pot) graph look like? Does anyone have a graph? Is it more of a linear type or audio pot? Tried searching on Google but couldn't find the graph. G Pot = W pot how ...
2
votes
3answers
306 views

how to make a W potentiometer from a log or linear pot?

My circuit needs a s-curve type of pot, that is a W pot but i cant find it in a store. How can i make a W pot Either using a log or a linear pot? w pot graph W pot=G pot Does anyone have a G pot ...
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1answer
96 views

potentiometer codes

I'm trying to buy 6 potentiometers from a local electronic store. All i have for the project is potentiometer codes , I'm not able to determine if its a log or a linear pot since there is code before ...
0
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1answer
156 views

Time Warp - Controling an analog clock from another room

My goal is to be able to spin an analog clocks hands forwards and backwards through a controller box that I build and wire to an analog clock. To accomplish this I imaging that I need a small hobby ...
2
votes
1answer
199 views

What type of potentiometer to use?

I'm making a Metal distortion pedal ill be using 6 potentiometers POT1 Distortion 250K POT2 low freq control 100K POT3 high freq control 100K POT4 mid 100K ...
1
vote
2answers
218 views

Which potentiometer to use?

New to electronics...so learning as I go. I have a 12vDC 1.5amp power supply that I will be using to power a 12vDC .30a computer fan. I want to use a potentiometer to adjust the speed of the fan but ...
0
votes
0answers
1k views

Arduino LCD not working

I'm getting started with LCD projects for Arduino, but for some reason, the LCD won't display characters. I'm using this tutorial from the Arduino website, and this LCD with an Uno R3 board. This is ...
3
votes
4answers
202 views

N-Ch FET with open-drain output

I stumbled across this line in this datasheet (page 10): Serial Data Output Pin. Internal N-Ch FET with open-drain output that requires external pull-up resistor. It shifts out the previous ...
3
votes
1answer
290 views

How to know whether a potentiometer is a linear potentiometer or audio potentiometer?

In general, how can you tell? As a specific example, how would I know from looking at the following datasheet? ...
0
votes
2answers
128 views

Continous rotary input?

I need something to work as an input for a rotary device. It must be able to rotate continously, accurate to a degree of rotation, and so that any extra full rotation will have no effect on the input, ...
3
votes
1answer
182 views

Making an adjustable resistance

In my latest circuit, I needed an adjustable resistance to adjust the ratio of a nearby ldr. It looks roughly like this: (btw, I'm not so sure that this schematic is correct. Feel free to fix it :) ...
2
votes
2answers
187 views

The influence of a potentiometer on photo-diode bias

I have a sensor which I have connected to an Arduino via SerialPort to get data readings. There is a "screw potentiometer" (It's a screw that changes resistance which affects the output voltage). If ...
1
vote
1answer
110 views

where to connect Potentiometer's pins

I was looking for a circuit to give me 1hz pulse for a digital clock and i found this circuit Right now I have no idea how to connect potentiometer, i haven't used one before. I'm trying to make ...
2
votes
1answer
250 views

Help Identifying 5K* Potentiometer

I am currently trying to replace a broken potentiometer in a therapy device ("KMI Hand mentor"). It is a 5k* potentiometer in plastic case/knob and comes in a through-hole version. The length of the ...
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votes
1answer
124 views

PIC24H POT input to control LED blink delay not linear

Hello I'm using the PIC24H microprocessor and I wrote a simple program that takes input from a POT using analog input which is then set to a modulus value of delay. It does seem to set the delay, but ...
3
votes
3answers
449 views

How to smooth potentiometer values

I have a linear actuator that has a pot in it. I am reading the value of the pot on my uC and I am noticing that the values are fluctuating wildly when the pot is changing (both up and down). The ...
2
votes
1answer
400 views

Building a skin resistance meter (not unlike Scientology type e-meter)

I am trying to build a scientology type e-meter which is based on a Wheatstone bridge with a quad opamp. It is designed to measure the electrical resistance of the skin of a person holding the ...
2
votes
2answers
509 views

Servo Controlled Potentiometer using Rotary Position Sensor

I need digitally controlled potentiometers but I want real pots and not a digital potentiometer chip because I want to integrate this with conventional relatively high voltage circuits like those you ...
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vote
3answers
298 views

Could a lamp plugged into an outlet be dimmed using a variable resistor?

If you had a variable resistor connected between a lamp and the wall, could it be dimmed with a variable resistor? Would it be practical, i.e. would it waste much energy? And would it affect both ...
1
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2answers
315 views

how to wire up potentiometer to subwoofer

I have a Audio-Taper Potentiometer that I bought from RadioShack and would like to hook it up in-line to my sub woofer so my 5.1 surround sound's bass is not so loud. However, the connections from ...