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.
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Why do I have to increase the current by 2V when I am using a transistor?
I have a 3V 3W LED, which I would like to control with an ESP32.
For controlling the LED, I have chosen a TP122 transistor.
Here is my 'schematic': (The Arduino is an ESP in real life, and the 3 V ...
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How do I create a circuit to reliably calculate a range of unknown resistances?
I've been dealing with this problem for quite some time now (3rd revision) and the results from my design are subpar. I'm designing a low power circuit which serves to determine the unknown resistance ...
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Testing to find polarity of PCB power connector
I've got a PCB I ordered from China. It required a 5V input voltage through a barrel jack. The issue is there is no sign showing the polarity (positive or negative center) so I don't want to connect ...
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Why is there a sudden drop at the rest initial point after discharging? (trying to find IR Drop of LIC)
I'm trying to get IR drop of one of my LIC cells.
After discharge, at the initial point of rest, I believe there should be a sudden increase in the voltage due to resistance.
Does anybody know why is ...
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How to find current for Thevenin equivalent circuit
I'm trying to figure out how to calculate the Thevenin equivalent circuit for a voltage divider like the following one:
I understand that V_th is obtained by opening the terminals of the output, so ...
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Soft-start circuit for highly resistive load - negating initial voltage spike
I am trying to design a soft-start circuit for one of my projects which has a relatively large resistive load (~1MOhm). I found the following example circuit from an answer for a previous post (12 V ...
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LCR meter U1733C - R range mesurement
I have the LCR meter "U1733C" and I am little confused about the "R" scale. As I understand (the manual doesn't say it clear - maybe it is self-evident and I am missing something) ...
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Resistance Vs Reactance Definition
I am trying to understand the practical distinction between resistance and reactance. As I understand from all what I read the resistance is responsible for the current flow and the reactance is ...
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Find equivalent resistance of a resistor circuit [closed]
what is the process for finding the equivalent resistance of the following circuit?
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Why does a line-tester glow more when I touch the steel door frame?
I reassembled my line tester, and it was then that I got to know how it actually works. I know that when someone touches the metal part at the top, the neon LED inside glows. However, I have seen that ...
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Trying to understand (and mimic) the multimeter's interference with a circuit
I am trying to use a microcontroller to regulate the speed control of a sewing machine, rather than the foot pedal that normally serves this purpose. The pedal cord has 2 wires that connect it to the ...
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Find R value from capcitor discharge plot obtained using scope
I'm using an oscilloscope with probes that are specified to have to have an input resistance of 10Mohms, I apply 5 volts (using power supply) in parallel to my capacitor and use the scope in parallel ...
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Total Resistance
How can I calculate the total resistance in each circuit, assuming that every resistor has the same resistance?
Are the diagonal resistors in parallel?
I do not have any idea, so every kind of help ...
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Adjusting underfloor heating thermistor resistance to match a different controller
I have DeviMat underfloor heating installed in my bathroom, presently matched to a Danfoss DeviReg "smart" thermostat. There's a matching Devi heating probe installed under the floor which I ...
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MCAT resistor question
Example: Consider two resistors wired in parallel with R1 = 5Ω and R2 = 10Ω. If the voltage across them is 10 V, what is the current through each of the two resistors?
Solution: First, the current ...
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