Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [resistance]

A measure of how much a conductor opposes current flowing through it. It can also refer to a part of a circuit, which has a non-negligible resistance value.

0
votes
1answer
19 views

Is it possible that a load can be destroyed if I am disconnecting all other loads in the circuit but one?

I consider myself as a beginner, so please don't be that hard to me. Can I theoreticaly destroy a unfused load if I disconnect all loads but one in the same circuit? In my understanding the current ...
0
votes
1answer
53 views

Multimeter not picking up a resistance

I am making a set of speakers using 34.5 AWG magnet wire, and neodymium magnets to make a voice coil. For my wire gauge and required length I should have ~3 Ω (DC), 4 Ω (AC). The issue is when I ...
0
votes
4answers
89 views

Why doesn’t a resistor drop all of the voltage in a series circuit?

Intro: I feel like there is one more thing that I really need to get a grasp of. Let’s say I have a circuit with a 5V battery and a LED that has a 3V forward voltage. Then before the LED is a ...
0
votes
2answers
64 views

Why is the current limited to 20mA when there are LED but 8.04 amps without?

NOTE: I HAVE ELECTRON FLOW ON INSTEAD OF CONVENTIONAL FLOW ON PURPOSE So I was making a circuit and it looks like this: As you can see 8.04A are flowing. That is ...
1
vote
1answer
26 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 ...
-1
votes
0answers
21 views

Analyze Series Circuit Graph [on hold]

Q2: Draw a series circuit to follow the graph given below (from points b through g). You can suppose (and must mention) the ratings of the resistors to be used in the circuit. In order to solve this, ...
-2
votes
2answers
63 views

How to remove 50 Hz, 100mV noise? [closed]

I am getting 100 mV noise signal at 50 Hz. I do not know the origin of the noise. What should I need to do to remove it?
0
votes
5answers
123 views

Confusion about Ohm's law and electrical power (basics of electrical engineering)..?

I am studying electrical engineering, but I still have some doubts about Ohm's law and electrical power. According to Ohm's law: \$I=\dfrac{V}{R}\$ So that means voltage is proportional to current. ...
0
votes
1answer
72 views

Thevenin Voltage and Resistance Problem

Please help me with this problem I have been set. So, I have successfully used Kirchhoff's Voltage law to determine the voltages and currents across each of the resistors in question (R2 and R3). ...
0
votes
1answer
43 views

Wattage in US vs AU/EU household appliances

This oven is listed in both the US and Australia. You can see that it's the exact same model (BOV845). Yet if you open the specifications, the only difference is that the US model uses 1800 Watts ...
1
vote
1answer
31 views

Conceptual Question About Hemholtz-Thévenin Theorem

I've been taught that for the Hemholtz-Thévenin's method I need to add an independent voltage source with a current flowing and at the same time "turn off" independent sources of voltage and current ...
1
vote
1answer
88 views

Resistors in series and parallel conundrum

Three resistors of some resistance (ohms) are put in series and the measured total resistance is 24 ohm. Now, if the same three resistors are connected in parallel to each other and the total ...
0
votes
1answer
100 views

Resistance reading on digital multimeter

I'm working my way through a beginners electronics book (to be specific it's 'Starting Electronics' by Keith Brindley). I've got up to the second chapter which introduces resistors and their colour ...
1
vote
1answer
120 views

Why do two different multimeters show completely different resistance readings?

I just received a brand new Brymen 869s and I'm concerned it may be broken as it's giving a strange reading. When measuring a 100k 0603 resistor which is soldered into a PCB (forming part of a ...
0
votes
1answer
38 views

Ouput resistance of a charger

I want to measure output of a charger (MODEL: GB28-25126) with below picture: When I connect my HIOKI multi-meter (3280-10F) to output of my charger in order to measure the resistance, it shows OF (...
0
votes
1answer
64 views

How does a ground node affect this circuits equivalent resistance?

I'm new to circuit analysis and I bumped into this problem that Im not sure how to solve. Originally the exercise had two ground nodes at the same ground level but I saw a thread that said that it ...
0
votes
3answers
36 views

Predictions based on resistance measurements not matching reality?

I'm using my multimeter to measure the resistance of my tongue, and leaving it on there for a full minute it seems to average out at around 1.5 Million Ohms. However, when I put a 9 volt battery on ...
0
votes
1answer
28 views

ITS-90 Tempature coefficents for a standard PT100 385 RTD

I'm currently using the ITS-90 formula to convert a resistance of an RTD to a temperature. I got the coefficients from the manufacturers calibration sheet. The problem is I have another probe that I ...
0
votes
1answer
58 views

What's the reason for this symmetry argument?

Okay so I've learnt about various methods to find equivalent resistance in circuit. But there's one particular argument which I don't understand and I would be grateful if someone will prove it using ...
0
votes
2answers
60 views

How to use a multimeter to test the resistance of my tongue?

I just purchased this cheap-o multimeter: https://www.amazon.com/AstroAI-Digital-Multimeter-Voltage-Tester/dp/B01ISAMUA6/ref=sr_1_1?keywords=astroai+am33d&qid=1551837071&s=gateway&sr=8-1 ...
1
vote
3answers
75 views

Chop Saw Inrush Current Limiter?

I have a Dewalt Metal cutting abrasive saw that tends to open a breaker on starting up. It draws 75A on startup tripping the magnetic part of the breaker and opening it. This circuit is only to stop ...
1
vote
0answers
40 views

Calculating equivalent resistance using loop analysis with no applied voltage

I have a bridge circuit that I am supposed to find an equivalent resistance between points K and P for using loop analysis. I am aware that a delta Y transformation is the much more direct route, ...
2
votes
1answer
66 views

Limiting current of a transformer used for resistance soldering

I'm working on a device capable of soldering wires to tiny components (3mm brass rings). I've used a PSU of a computer to make a resistance soldering device. Using the 5V line and a graphite stick of ...
0
votes
0answers
18 views

Resistance with ENC to RJ-45 hookup

I'm wondering since the Tpin+/- and Tpout+/- pins default uses 49.9 ohm resistors. Since the resistor I have that is closest to 49.9 ohms is 47 ohms. Is 47 ohms won't be any problem? Datasheet with ...
-2
votes
3answers
142 views

Resistor network - how do I reduce this?

How do I find the value of this resistor network. Is the 10 ohm resistor in parallel with the 20 ohm resistor? Is the 16 ohm resistor in parallel with the 5 and 20 ohm resistors in series? I can't ...
1
vote
1answer
80 views

Fuel sender - need something to convert ohms to volts?

I need to connect a cars fuel sender(ohms) to a analog input on a GPS tracker (volts) Here's the catch, in our tests most fuel senders we worked with seem to send the data as ohms/resistance However,...
1
vote
1answer
53 views

How to power an electric motor

I would like to attempt to assemble an outrunner BLDC motor from scratch. Its working principle seems ridiculously simple and I'm up for the challenge. There is one thing that I would like to clear up ...
0
votes
1answer
45 views

What resistance would I need?

I'm kinda new to PCB design, but here we go: I've created a simple sub-pump water level monitor and it uses a constant 5V from a MOSFET. In the end, it's all monitored by a raspberry pi and I know if ...
1
vote
1answer
38 views

How do I find the Thevenin voltage and resistance equations of this circuit?

How do I find the Thevenin voltage and resistance equations of this circuit, with respect to the terminals U and G when Rc, Vc, Rt, and Rtrans are given?
1
vote
0answers
66 views

Finding equivalent capacitance and resistance from DC circuit with combinations of R and C

In order to get the simplest RC circuit and get equivalent circuit tau: How can be its transient studied if before t = 0 there only exists one resistive part of circuit? I's obvious that before t = ...
1
vote
2answers
92 views

How to take resistance reading when value is effected by measurement?

Context I am trying to measure the wiper resistance of a potentiometer. This is performed by leaving the potentiometer wiper in one position, and measuring from each terminal to the wiper (\$R_1\$ ...
-1
votes
1answer
88 views

BJT amplifier design with input resistance, output resistance, and open-loop gain requirements

so currently i'm designing a BJT Amplifier with these requirements: Open-loop gain = 35 dB Input resistance = 600 Ohm Output resistance = 200 Ohm Another thing is the only BJTs I can use have hFE of ...
-2
votes
1answer
50 views

Calculating inner resistance of a linear dipole

I've been stuck on a question for a while now, so I'd really appreciate if you could take a look at this: I'm supposed to calculate the dipole's inner resistance. I've got that E= 15V, R1= 1200 Ohm ...
2
votes
3answers
102 views

What is the value of the given resistor?

I tried checking with 5 band color code but was unsuccessful. Resistor is blown hence the value cannot be determined using multimeter.
1
vote
1answer
51 views

How to find current through series of potentiometers, and if it is safe for potentiometers? (Arduino)

I have 9 potentiometer with the specs: 10k Ohms and 0.5W I'm using an Arduino Mega, and using it's 5V port output to power these potentiometers in series, and I saw online that the max current this ...
0
votes
2answers
39 views

measuring resistance on hv transformer

I need to verify the resistance on a HV transformer that receives 208v single phase through terminal 1 and 2, or 240v through terminal 1 and 3 and delivers 4000v through terminal 4. As per the ...
0
votes
1answer
75 views

Can a 125mw dual gang pot handle 10w audio output?

I want to build balance control for two audio amplifier circuits, and I want to use dual gang pot. I want to know if I connected it directly to the outputs of the two audio amplifiers circuit then to ...
0
votes
1answer
38 views

How to evaluate equivalent insulation resistance of two cables?

My guess was that the equivalent insulation resistance of two cables in parallel is same as the equivalent resistance of two resistances in parallel. But instead it is the sum of the two insulation ...
2
votes
2answers
95 views

Measuring the resistance of USB car chargers

I have a few USB chargers that are powered through a 12 V car receptacle. I measured their resistance with a multimeter, applying the probes to the contacts of the 12 V input. One of the chargers had ...
0
votes
0answers
41 views

Voltage and amperage requirements for resistance heating of glass

I am planning to introduce electric heating/boosting in my glass melting furnace. The present temperature of the glass is around 1200 deg C and I need to raise it up to 1300 deg C. I am trying to get ...
0
votes
2answers
84 views

Can a 3W pot be connected to a 5W LED baton? [closed]

Situation: I got a LED baton and the brightness was higher than required. I added a regular 22k pot in series to it, and achieved lower brightness, but within a few seconds, the pot was burnt. I ...
2
votes
2answers
195 views

LED Blinking after replace

For clear any mistake, the question is: Why the LED started to blink after being replaced? The goal was to replace the blue leds with red leds, after replacing the leds one of them started to blink, ...
1
vote
2answers
90 views

Create a simple resistive heating element on PCB with Altium

I have created a component with a simple pattern using tracks and arcs as shown in the link below. How to Build Custom PCB Heater Elements However, Altium DRC is throwing errors since I have used 2 ...
0
votes
2answers
37 views

Powering an IR + RED laser with an Arduino

I am hoping to run a laser diode from an Arduino. The specific one with included data sheets are here: https://industrial.panasonic.com/kr/products/semiconductors/laser/red_infrared/red-and-infrared-...
1
vote
0answers
52 views

Electric heating for glass melting furnace

Some furnaces use electricity for glass melting. Low voltage and high amperage power is passed through the molten glass through 2 molybednum electrodes dipped into the glass. The molten glass acts as ...
1
vote
1answer
121 views

How to solder resistance wire?

For the kids of my electronics tinker club, I thought it would be a great experiment to see how the resistance of a wire is proportional to its length. Therefore I made a very simple circuit ...
0
votes
2answers
51 views

What should be the output resistance of this source with series diode?

Below shows three sources with open terminals: simulate this circuit – Schematic created using CircuitLab In Figure 1 if we want to calculate the output resistance, according to the linear ...
0
votes
3answers
90 views

Basic resistor question for parallel LED circuit

I'm planning on building an LED circuit to place inside a model miniature for wargaming. The circuit would be in parallel as I'd need a really big battery to power up all the LEDs. I wanted to check ...
0
votes
2answers
48 views

Am I misunderstanding steady state power disspation calculations?

I am looking at the Littlefuse 5KP series. It says on the datasheet: I am trying to understand how they arrive at \$P_D\$ = 8.0W. Given thermal resistances of 40°C/W or 8.0°C/W, and 100°C ...
0
votes
2answers
83 views

PC fan speed control

I am making a stir plate out of an old PC fan, variable resistor, and DC power supply from this tutorial. I have two power supply's to choose from, their outputs are: PS1 = 12Vdc, 2A PS2 = 12Vdc, ...