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Questions tagged [rheostat]

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Rheostat with parallel resistor, how to make the taper more linear?

I'm using a 10k potentiometer wired as a rheostat in parallel with a 470 ohm resistor, because I need a (roughly) 500 ohm variable resistance in a circuit. The type of potentiometer I'm using is not ...
one_three_three_seven's user avatar
4 votes
4 answers
983 views

Is it OK to leave one of the potentiometer pins open in this case?

I want to use two potentiometers to limit current and fine tune the load of a basic photodiode circuit. The diode specifications and the voltage values are not yet clear but I want to use two ...
user4444's user avatar
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2 votes
1 answer
104 views

How to handle PCB design rule check when using a potentiometer with only two pins as a rheostat?

As a part of a simple PCB, I want to use a potentiometer as a rheostat which will vary the feedback resistance of a Schmitt-trigger as follows: I use KiCad and if I leave pin 3 open as shown above, I ...
user16307's user avatar
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2 answers
172 views

How to select correct resistor to protect potentiometer?

I'm planning to use potentiometer in a circuit. I know when potentiometer reaching low resistance, big current/power could burn potentiometer. How could I select correct resistor to protect my ...
jjk's user avatar
  • 123
0 votes
2 answers
502 views

Measuring voltage across a rheostat

I want to measure the voltage across a rheostat. For this purpose I connected a voltmeter in parallel to it, but even on turning on the circuit there was no deflection in the voltmeter whatsoever. ...
NewUser25's user avatar
0 votes
3 answers
213 views

Can a rheostat (as an alternative to a relay) act as the correction unit in a thermostatically controlled electric heater?

I was studying about the various elements present in a thermostatically controlled electric heater control system. While I agree that a relay can be used to correct the output temperature from a ...
Sheraz Malik's user avatar
0 votes
2 answers
445 views

Variable resistor that will not 'crackle' with DC when adjusted?

When using a standard carbon potentiometer as a variable resistor it will 'crackle' if exposed to a small DC voltage. The DC is unavoidable and the circuit functions as desired except for this '...
Albert's user avatar
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0 answers
64 views

Rheostat circuit help

How much can I actually vary with this rheostat and what resistance value should I make it to get precise control of the RPM of the motor- maybe control in +100RPM by varying resistance and then ...
Edwin 's user avatar
0 votes
1 answer
111 views

Choosing rheostat ratings

I want to control a heated pad with a rheostat. My heated pad has a power rating of 30W and supply voltage of 12V DC. How do I calculate the ratings required for my rheostat and plug adapter? I have ...
Jane's user avatar
  • 11
1 vote
1 answer
547 views

Op-amp for amplifying a low voltage DC input

I have a 0.1-4.4ohm rheostat I need to feed to an ADC(assume 10 bit) within a microcontroller. I will do some maths with the counts and eventually set digipots to control some external equipment. ...
Dustin Goitia's user avatar
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0 answers
71 views

LM317 vs Rheostat

I am trying to limit the voltage to a 12 volt , 25 watt silicone heating pad. I am trying to decide between a rheostat and an LM317 voltage regulator which I would control using an external ...
Oscar's user avatar
  • 91
0 votes
1 answer
174 views

Power transistor or voltage regulator as alternative to rheostat [closed]

I need to modulate the voltage to a 100 watt 12 Volt DC vacuum pump. I bought some potentiometers before realizing that the wattage they were rated for was too low, and that I needed a proper 100 watt ...
Oscar's user avatar
  • 91
2 votes
1 answer
427 views

Is this explanation of the workings of a rheostat consistent with the diagram?

I came across this description of a rheostat along with a diagram: ...The best example is the traditional dial controlling volume on a radio. The outer ring, or toroid coil, consists of a resistive ...
puwlah's user avatar
  • 115
1 vote
1 answer
47 views

Rheostat for a wire feed

I have a 16 ohm 1.25 ampere 25 watt rheostat that has gone bad. Is it okay to replace it with a 16 ohm 1.7 ampere 50 watt rheostat?
Ahaze's user avatar
  • 11
0 votes
3 answers
176 views

Can I safely balance a series/parallel cell circuit to power a 12V soldering iron?

I want to power a 12V soldering iron with 2x 21700 '40T'batteries and 3x 18650 '25R' batteries with a torroidal rheostat between them. The 3x25R batteries will be in parallel. The rheostat will ...
Samuel Drew Crow's user avatar
2 votes
4 answers
445 views

Using a potentiometer to control greater resistance

This is more a theoretical question: Let's say we use a potentiometer as a variable resistor. We can set it from 0% (0Ω) to 100% (let's say 1Ω for simplicity). Using this pot we can reduce the total ...
flawr's user avatar
  • 721
4 votes
2 answers
446 views

Can this WWII era rheostat be modified to dim an LED bulb?

I have a WWII era RAF chart-board lamp in perfect unused condition. I want to use an LED bulb with the original dimmer as tungsten runs so hot. I want to avoid rewiring or bypassing the dimmer as the ...
Walter Hutton's user avatar
0 votes
0 answers
238 views

why wouldn't a 9-60DCV 20A PWM motor control work to control a 12v 20A wiper motor [duplicate]

I have a question regarding controlling the speed of a wiper motor with a PWM vs wiring in a rheostat in the positive side. I have a 110ACV-12DCV 20A converter going to a 9-60DCV 20A PWM motor ...
Philbus's user avatar
  • 89
1 vote
1 answer
134 views

AB 984246 8821 Allen Bradley

In Bayliner boat OMC stern Drives, the trim sensor used an Allen Bradley potentiometer/rheostat. The number on the back of the case is: 984246 8821 J. I believe it is a reverse log design with a 'D' ...
Tony Roussos's user avatar
0 votes
1 answer
472 views

what would happen if I used a rheostat in series with a motor to drop my 230v ac supply to 110v ac?

I realize that I would be running higher (a little more than double) current through the motor I'm just curious if it would damage my motor? The motor is a 1 hp, 110V/60Hz driving a meat grinder.
Ping's user avatar
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1 vote
1 answer
65 views

Resistance/Voltage relation in Rheostat?

According to "How Computers Work" (Tenth Edition) by Ron White, he features a graphic of a potentiometer with three terminals on the bottom with the one on the left being for current flowing in and ...
Tristan's user avatar
  • 13
1 vote
1 answer
92 views

Rheostat with Hydraulic Amplifier Card

simulate this circuit – Schematic created using CircuitLab I am designing a control system for a Hydraulic Valve Amplifier Card (Bosch VT-VSPA2-1) and I need to send an analog input signal to ...
JCR's user avatar
  • 15
0 votes
0 answers
36 views

Q: Unexpected behavior from digital Rheostat

I have no idea whats warranting this behavior from the MCP4162 device Starting from 500mV(pp) - 2.8V(pp) a weird "wave" like distortion happens in between the two voltages. (Towards the negative ...
Leoc's user avatar
  • 1,421
0 votes
1 answer
448 views

Dc motor as torque transducer for BLDC motor

I bought a cheap BLDC motor on some Chinese website and could not find its characteristics. However, I have A28-400 24V amp flow Dc motor with its characteristics. If I'm able to build a test rig to ...
Raul's user avatar
  • 3
2 votes
5 answers
1k views

Choosing a rheostat

I have a cartridge heater with the following specs: 50W and 220V AC. I would like to control it with a rheostat, but I am not sure how to pick an appropriate rheostat. Could someone give me a hand?
JJuradotx's user avatar
0 votes
2 answers
135 views

What would I use to regulate raise/lower temperature in an AC 40 watt device's heating element? [closed]

It's for a resin burner--frankincense etc--that doesn't have a temperature regulator so it burns too hot. I don't need to know an actual temperature, just to be able to raise/lower the temp'. Thanks.
Alpharalpha's user avatar
0 votes
2 answers
327 views

Rheostat replacement resistors with relays

I would like to replace a 500k rheostat with three fixed value resistors. Can I achieve this with the help of 3 sugar cube relays like I've shown in the picture? or is it bad idea? Those relays are ...
Kokachi's user avatar
  • 694
3 votes
3 answers
5k views

0-10V Digital Rheostat for LED Dimmer?

I have an LED light with a power supply that follows the ISO 60929 0-10V standard for dimming. The manufacturer says "the power supply is current sourcing, and is roughly 0.5mA." The following ...
par's user avatar
  • 275
2 votes
1 answer
2k views

Current limiter for homemade arc welder

I'm would like to control the AC current that is will be consumed by a homemade arc welder. Website I used as a reference: http://www.mike-worth.com/2013/07/31/adding-a-current-limiter-to-my-mot-...
invulnarable27's user avatar
0 votes
4 answers
4k views

Rheostat power rating vs. current rating

I have a 1k ohm rheostat that has a 25W power rating, and a current rating of 0.15 amps. I got it because I was running a 12v/24v circuit at 1amp draw. I just looked at the power rating of 25W and ...
Owen's user avatar
  • 103
1 vote
2 answers
4k views

reducing a 12volt fan speed

I bought a 12volt, 80 watt aftermarket fan for a car. What I'm making is a portable swamp cooler for my tent when I move to AZ this summer. I plan to charge a 30 amp, deep discharge trolling motor by ...
keith's user avatar
  • 11
1 vote
2 answers
3k views

Purpose of rheostat in measuring resistance

I was given task to measure the resistance of different length of same conductor to find the relationship between length and resistance. The circuit diagram is something like this: The resistance,R ...
JF9199's user avatar
  • 11
1 vote
1 answer
200 views

What does this denote in the schematic?

I am designing a PCB for a VFD clock I want to build and I have come across something in a schematic for a voltage regulator that I have no idea what it means. I have circled what I do not understand ...
LifeEscalade's user avatar
3 votes
3 answers
4k views

How much power is wasted with a light dimmer?

I have my rotational light dimmer and am wondering the logic behind it. If it is a potentiometer, when fully off, it should be wasting lets say 50V of power if not using a transistor. By logical ...
Blake's user avatar
  • 503
1 vote
1 answer
203 views

How to amplify the resistivity range of a rheostat

I have a black box DC to AC inverter with a 5 kΩ linear taper pot wired to it that acts as an LED light dimmer. I have no idea how the circuitry of the black box is composed - it is encased in a ...
Doug Coburn's user avatar
1 vote
2 answers
5k views

Is there any difference between the terminals of the rheostat

This is probably a dumb question but I just wanted to be sure for my practical exams. Is there any difference between the upper or the lower terminal of the rheostat? Are you supposed to connect the ...
user2468338's user avatar
24 votes
2 answers
13k views

Why would you short two pins of a potentiometer?

I've found a potentiometer which controls the heat of a cook top. One of the outer pins and the centre pin were shorted with a soldered jumper. Why would someone do that? What does this achieve?
user1937747's user avatar