Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [rheostat]

34 questions
23
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2 answers

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
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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 original cabling is in such good condition. The…
Walter Hutton
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3 answers

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 diagram is representative of this circuit. The power…
par
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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 design: 1) Should it have an extremely low voltage…
Blake
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1 answer

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 wire wrapped in a spiral about a ring of…
puwlah
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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 range of resistances covered by the 0% to 100% by…
flawr
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5 answers

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
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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-welder/ He converted a transformer to a rheostat (blue…
invulnarable27
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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. The rheostat is on the headlight dimmer switch of a…
Dustin Goitia
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1 answer

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
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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' shaft. I'm not sure I can trust my measurement as…
Tony Roussos
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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 the center terminal connected to a wiper for…
Tristan
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1 answer

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 the card, which the card translates into valve spool…
JCR
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2 answers

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 both a 400 watt power inverter in my car, as well…
keith
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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 is replace with different length of the conductor …
JF9199
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