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Questions tagged [resistors]

A resistor obeys Ohm's law (V=IR); the current through it is equal to the voltage across it divided by the resistance (equivalently \$I=\frac{V}{R}\$)

-2
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0answers
39 views

Resistors in Arduino kit

I want to run my power supply using 10-ohm resistor but I don't have a 10-ohm resistor in my Arduino kit, I am wondering if that is possible to use 100 ohm?
14
votes
3answers
2k views

Is this resistor leaking? If so, is it a concern?

I found this resistor on the control board of an old Whirpool washing machine: Is that fluid leaking from the resistor? (Why would that happen?) Could it be something like stray epoxy or a chemical ...
0
votes
2answers
56 views

Stove element as a resistor

I am wanting to use an inverter based TIG welder as a constant current power source for anodizing aluminum. The main hurdle I suspect I will be facing is that the amperage of the welder may be ...
0
votes
0answers
35 views

How make a pulse acquisition from an electrical meter directly into a raspberry pi?

I would like to acquire pulse informations from a french electrical meter. There is a picture of the outputs of this electrical meter. These pulses vary in frequency and after acquisition, we can ...
1
vote
4answers
576 views

High resistance, no current. What's the point of a potential then?

I am referring to this example: Why does it matter that the IC has a high resistance? What does this do for/to the IC? If there is a potential but no current, what is the point of using the IC when ...
0
votes
2answers
73 views

Connect 10 LEDs using 5 volt current

I have 10 yellow-colored LEDs and ten 220 ohm resistors. I don't have any power source except the Arduino's 5 volt itself. Is it possible to power all the 10 LEDs using the 5 volt equally? Or will ...
0
votes
2answers
75 views

Design a Circuit with Zero-Order Transfer function H(s) > 1

I know that if I do 2 1K ohm resistors in series, I can just do a voltage divider to get Vout/Vin = R2/(R1+R2) = 0.5. But if I want to get a transfer function of 3, what components would I use?
1
vote
3answers
109 views

How to figure out what resistors are in the E12 and E24 series?

Is there a way, other then remembering, to figure out what resistors are in both of these series?
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0answers
44 views

Solving a circuit with two power sources and three resistors, trying to find Vout [on hold]

Consider the electric circuit shown in Figure 6. Find the expression for the output voltage Vout as a function of voltages V1 and V2 and resistances R1 and R2. I just am confused about how the ...
0
votes
0answers
19 views

Finding current of circuit in steady state

I am unsure if I did the KCL correctly. Also if I switched from rectangular to polar without mistakes. Excuse me if the work is a bit sloppy I am new to the polar and imaginary coordinates.
4
votes
4answers
824 views

Which values for voltage divider [duplicate]

I just learned about voltage dividers and how to calculate the relative values for the resistors to use. For instance, to go from 5v to 3.3v I could use a 1 kohm and a 2 kohm resistor. However I could ...
0
votes
2answers
55 views

Voltage spike at the coil when opening the switch [duplicate]

I've the following circuit: simulate this circuit – Schematic created using CircuitLab In my book they stated the following sentence: After that the switch is closed for a long time, I let ...
1
vote
1answer
43 views

Voltage exceed source voltage over a coil when opening a switch

Well, I have the following circuit: simulate this circuit – Schematic created using CircuitLab When the switch is closed for a long time, the current that is flowing trough the resistor \$R_1\$...
0
votes
1answer
49 views

What happens if a resistor or LED if it breaks in a circuit in regards to design C and B [closed]

In general, what happens to the overall current and the current and voltage going through each LED if a resistor or LED breaks in a configuration C and B? Assuming that the voltage source is constant, ...
0
votes
2answers
58 views

Finding time constant in terms of R and C

I got a different expression for the time constant than the actual solution. Can anybody tell me where I went wrong? Why is it that in the solution all three resistors were put in parallel? What do ...
0
votes
2answers
70 views

Current in charged RC circuit

I've the following circuit: simulate this circuit – Schematic created using CircuitLab The capacitor is charged up to 10 V according to the following formula (when the switch is closed): $$\...
4
votes
3answers
852 views

Resistor Selection to retain same brightness in LED PWM circuit

I am making a simple LED PWM brightness control circuit. I am using a relatively high power White CREE LED, N-channel Enhancement MOSFET BSS316N and Resistor R. The circuit is as shown below. I am ...
0
votes
3answers
58 views

Under open-circuit conditions, does a transformer behave more like a resistor, capacitor, or inductor?

I have the below schematic showing the equivalent circuit of a transformer under open-circuit conditions. Will the transformer behave like a resistor, inductor, or capacitor? And will this behaviour ...
0
votes
0answers
25 views

STM6600 voltage divider on VCC for high voltage applications

I'm evaluating the STM6600 on/off controller. My application has a 2-series LiPo battery with a voltage range of 6 to 8.4V, so I need to put a voltage divider before VCC as described in AN3271 (...
0
votes
2answers
54 views

Sansui AU 6600 Amplifier restoration Power cement resistor tolerance

I am restoring my Sansui AU 6600. On the f 2097 driver and power supply board there are four(two for each channel) 3W cement resistors rated at 0.47 ohm I took all four out of the circuit and tested ...
2
votes
2answers
92 views

How to reduce thermal resistor noise in filter circuit?

I'm taking some measurements from a bio-sensor (using an INA) that operates on the a few to \$100\ \mu V\$ scale. Because of 50/60 Hz EMI, I plan to apply a notch filter (NF) of the Twin-T or the ...
2
votes
3answers
83 views

Mathematical help with Wheatstone bridge

This is a homework, so I won't ask for a complete solution, but can anyone tell me how should I approach this? I've been sitting now for hours without any progress, all that I know is the answer ...
0
votes
0answers
55 views

Finding the voltage across an inductor in a RLC circuit

Well, we have the following circuit: And I need to find the voltage at the node \$\text{Y}_1\$. My Work: The input voltage and current relation is given by: $$\frac{10}{s}=i_{in}(s)\cdot\frac{1}{\...
0
votes
0answers
51 views

Purpose of resistor in open collector

I am comparing breakout boards for VL53L0X sensor by different distributors. Below is from Pololu: What is resistor R7 marked above for? This is not present in Adafruit's schematic. Also not present ...
-1
votes
2answers
99 views

Pull up resistor for 555 Timer IC

https://makezine.com/projects/laser-tripwire-alarm/ I need help determining the pull up resistor needed for this circuit. It uses a 555 Timer IC. The resistor R1 acts as a pull-up resistor for pin ...
0
votes
1answer
56 views

How to solve infinite grid with the observing terminals at diagonal of infinite square matrix?

The answer given is 2/3ohm solution is not given but I can expect how they got that answer but can't justify the way.
0
votes
2answers
31 views

For a thick film resistive element does the surface area of electrical contacts affect resistive value?

I am learning about film-based heating elements and they are challenging my understanding of electronics a bit. I am used to thinking about resistors and wires on a schematic and I am not used to ...
0
votes
0answers
59 views

Determine the Value of R for the following cases:

I am unsure how to find an exact value for R, even if it is in terms of the other two variables.
2
votes
0answers
104 views

Discharging high voltage and capacitance capacitor?

I need to discharge a 4.4mF (millifarads) capacitor storing 1200V in about 5 seconds. I did the t=R*C' and got a resistance value of approximately 227ohms. I did a ...
2
votes
3answers
97 views

Identify resistor with faded color bands

I would like to replace this resistor, but its color bands are faded. Does anyone know what resistor I should get for R31? Thanks.
0
votes
3answers
122 views

Why doesn't the voltage drop across the resistors of my battery charger follow Ohm's law?

Here's the setup, the three items below are in series: Battery at 215V Power supply at 250V (It is a 5A constant current power supply that will drop voltage down to 200V minimum before failing) 8 ...
7
votes
1answer
2k views

Why does this rising edge detector using a capacitor and a resistor work?

So in this video from Ben Eater he makes a rising edge detector using a capacitor and a resistor like the one below. simulate this circuit – Schematic created using CircuitLab In the video Ben ...
1
vote
2answers
152 views

Can anyone identify the resistors in the picture?

Can anyone identify the resistors in the picture ?
0
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2answers
41 views

Measuring variable resistance as voltage value

I would like to replace the microcontroller of an old gamepad with a Arduino/Teensy board. To do this, I need to connect all buttons and the output of the 4 potentiometers of the gamepad's joysticks ...
0
votes
0answers
53 views

Interchangeable resistor

I have a PCB board where I am measuring the voltage drop across a resistor which is placed on the Vdd path of a small micro-controller. I would like to have a method for easily interchange the ...
0
votes
1answer
51 views

Leds blink with a different power supply

I made a led circuit in parallel with a power supply of 12v 2a. But there is the problem, I’ve changed the power supply. Still the same value of 12v 2a but my circuit doesn’t work. I’ve tried a lot ...
0
votes
1answer
46 views

Capacitor in series with voltage divider

I am trying to understand the dynamics in the following circuit: I have a voltage source here. Now, I measure current at C1 and voltage at C1/R2 and the result is this: So, what I understand so far ...
-6
votes
2answers
105 views

Which resistors to use for high current (10A) voltage-divider? [closed]

I'm having a problem determining resistor specs (especially wattage) for my voltage divider circuit [ 27 V to 17.5 \$+-\$ 0.5 V ] on 10 ampere DC supply. I have an AC (220V 50Hz) to DC (27V 10A) ...
9
votes
2answers
1k views

Could the terminal length of components like resistors be reduced? [closed]

When breadboarding the length of the wires on resistors (through-hole) is quite comfortable. The same holds for other components like diodes or capacitors. I presume the terminal length was made to ...
0
votes
3answers
72 views

Proper resistor(s) for limiting LED brightness

I have an LED powered by a serial(Rs-232) port on my PVR. The light is connected to the DTR pin through a 1k\$\Omega\$ resistor. It is set up this way in accordance with the instructions for the ...
8
votes
9answers
3k views

Negative Resistance

I am a bit confused about the physical meaning of negative resistance. Mathematically, a component which has negative resistance shows a decreasing voltage across its terminal when the current inside ...
0
votes
1answer
61 views

What component should I use? H-bridge? Relay?

I am working on a senior design project that involves regulating the noise from headphones to make sure no damage to the ear is done. I have all parts working except the part necessary to switch the ...
0
votes
1answer
30 views

Common base bias divider resistances

I have been trying to grok the common base amplifier, and put together a few examples, but there is something that I do not get at all. I have the setup below. Things are working more or less as ...
-1
votes
2answers
83 views

Will a resistor allow the battery to last longer?

3V 25mAh button cell battery, a single 3-3.4v 20mA UV LED. If I put a 1/8W 1 ohm resistor in the circuit will the battery last longer?
0
votes
1answer
31 views

Integral in mathematical expression of capacitor/resistor LTSpice

I know how to simulate a variable resistor in LTSpice. For example for a heating resistance the equation can be made by considering heating equation and can be expressed like R=(Ri-Ao*EXP(-time/To)) ...
0
votes
1answer
126 views

Do the resistors fail to distribute voltage?

I am working on infrared array PCB designed to track line i was supposed to get analog output (1 in the diagram) instead i get all 5 volts from all sensors in my PCB. I bought a infrared sensor ...
1
vote
1answer
55 views

Is there a difference between a tempco resistor and a thermistor?

That is, other than just the nomenclature.
0
votes
1answer
61 views

How do I find the right resistor for an LED panel? [closed]

I purchased one of these cheap LED panels to light a room. One review suggested that it's important to put a resistor on it, to keep it from frying itself. But, he didn't list what resistor to use. ...
3
votes
4answers
4k views

How is the internal pullup resistor in a microcontroller wired?

I am constructing a circuit where 2 microcontrollers will communicate with a high or low state on their IO pin. Basicly a state pin for Bluetooth connected, or not. One microcontroller will have an IO ...
1
vote
1answer
49 views

Choosing inrush current limiting resistor for a mains rectifier

I am having a trouble with a mains rectifier. Simplified schematic: simulate this circuit – Schematic created using CircuitLab Only problem I have is that R1 sometime explodes during circuit ...