Questions tagged [voltage]

Voltage, otherwise known as electrical potential difference (denoted ∆V and measured in volts) is the difference in electric potential between two points (adapted from Wikipedia). Voltage can be constant (DC) or varying (AC).

Filter by
Sorted by
Tagged with
1
vote
1answer
57 views

why do we assume that V is zero

in the photo below under the diode (D2) we're given V and to help solve for current V is equal to zero in the solution. How can we assume V=0 if it's not given in the question?
0
votes
2answers
79 views

Is It Posible To Have Step Up Power Supply Without a Transformer?

I am trying to design a high voltage low current power supply. My purpose is to design it without a transformer. For example circuit like this : My input is 220V AC after this circuit I am going to ...
0
votes
2answers
65 views

How to measure high current (20A DC) using arduino

I would like to be able to measure the power of a load connected to a 12V battery - this load takes around 20A and I would like to be able to store this using an arduino. My first attempt was using a ...
0
votes
0answers
42 views

Voltage regulator between two circuits

I am pretty new to electronics and got stuck on a probably very easy issue, however I could not find a proper answer for it on google. Basically, I have 2 circuits, one, which operates on 24V, and an ...
0
votes
1answer
47 views

Fixing a TV remote with a low voltage button

I'm trying to fix my TV remote (Panasonic Viera) as one of the buttons has become unresponsive. I've cleaned it with alcohol and noticed the voltage across is just 0.3V rather than 2.7V across the ...
1
vote
1answer
34 views

Expert advice needed on electric bike battery setup

I'm currently building an electric bike for a competition. I know I want a 15s lithium ion NCM battery (max 4.2 volts/cell), but don't have a battery management system or a balance charger than can ...
0
votes
0answers
39 views

How to connect 2 hot wire to a 2 pole MCB? [migrated]

how can i connect 2 hot wires to a 2 pole MCB? What is the output of 2 pole MCB ? Will it be the same as 2 hot wire output or can connect to a LIVE and NEUTRAL terminal?
0
votes
4answers
88 views

Why can we see the current source as a open circuit and voltage source as a close circuit?

What is the \$R_L\$ value can maximize the power of \$R_L\$? simulate this circuit – Schematic created using CircuitLab The solution: simulate this circuit \$R_{th}=1+2+1=4\$,so when \$R_{L}=...
0
votes
1answer
25 views

Trying to understand how they got equation for Vzo

this might seem like an easy question but I'm still new to circuits and I'm trying to understand how they got the equation for voltage. They have the solution as 6.8=Vzo+5m(20), but when I looked at ...
-4
votes
0answers
45 views

Voltage in parallel circuits [closed]

Is the voltage source in a parallel rlc circuit the same as the voltage across all components? All I can seem to find is that voltage is the same across all components but not whether or not I need ...
0
votes
0answers
33 views

Converting a circuit/ schematic onto a breadboard? electronics basics

I need to produce a complete breadboard for my coursework but due to missing school (leg injury) I don't understand how to convert my circuit/schematic into a breadboard after trying to look online I'...
0
votes
3answers
50 views

what does pull-up resistor and pull-down resistor mean? How do I implement them in my circuit?

I am trying to understand the basics of electronics and I often come across the terms pull-up and pull-down resistors. From what I understand these resistors help the switching logic devices like ...
0
votes
2answers
74 views

What purpose is there for having current flow in this direction for an Op-Amp

for the given schematic my professor had current flow from R2 to R1 when attempting to finding voltage gain. I'm just wondering why he goes from R2 to R1 and not the other way around. I know you can ...
0
votes
2answers
58 views

The solution use Thevenin's theorem to solve the problem,but i can't understand why

This solution use Thevenin's theorem to solve the problem,but i can't really understand its meaning ,hoping someone can explain them to me! Question:determine the I value Sol: \$R_{th}=2//4=\frac{4}...
0
votes
1answer
49 views

Requirements for closed, open, and short circuits

In terms of understanding paths in a circuit, let's take a few example circuits: (1) Would the following circuit be considered closed or open (or something else) since it doesn't have a voltage ...
2
votes
0answers
28 views

Inductive Crankshaft Position Sensor Voltage Drop When Split Between Inputs

I'm working on a project with a vehicle using two engine control modules, which both need accurate crankshaft position signals to function. Adding a second sensor is not an option. The sensor is an ...
1
vote
1answer
139 views

Should a grounded case have voltage across it?

Ok so simple question though it might seem stupid. I'm wiring up a simple metal enclosure with a control unit inside. AC current from the wall, 240v~ to the unit. I'm containing it in a metal case ...
1
vote
3answers
43 views

SMPS Input/Output ripple current and ripple voltage

I found a presentation regarding SMPS and found this slide. I am not totally able to grasp the concept of the input and output ripple current. In the above image I have the following questions : I ...
0
votes
0answers
51 views

How do we find where the average voltage resistor load formula came from?

Applying the half wave rectifier. We have in series a source called \$V_{in} \$, a diode and the resistor load. To find the average resistor load we use this formula : \$(V_{max} - 0.7) / \pi \$ I ...
0
votes
0answers
54 views

Multimeter capacitance value - ADC readings

I have set up my raspberry pi to read from the MAX1204. To know if I'm reading the proper value, I use a multimeter at the input channel of the ADC, and compare it to what I read through my program. ...
1
vote
1answer
98 views

Linear regulator heats up at 60 volts

MY goal is to design a regulator which could receive (12 V to 60 volts DC as an input) and 5 volt with 60 to 70 mA current as an output. The reason I used three BJT's NPN (Q1, Q2, Q3), so I thought I ...
0
votes
1answer
44 views

What supply voltage for the Abracon crystal oscillators?

I'm considering the Abracon ABM8W-13.5600MHZ-4-B1U-T3 Crystal but I'm having difficulty finding the maximum and minimum supply voltages. Does anybody know how to obtain this information (I've tried ...
3
votes
6answers
1k views

Why does voltage sign matter for electrical devices and components

If you look at the specifications for certain electrical devices, computer hard drives for instance, the voltage requirements would be something like +6.6v or +12v. Why does the sign matter? Why ...
0
votes
1answer
51 views

How long will a 32v 15A (500Wh) e-bike battery last outputting at 5V 1A?

I hope it's okay to ask this here My e-bike has a Lithium Ion battery (32 Volts, 15 Amps), and it has a USB-A output, marked as 5V and 1A, I have 3 questions: How long will this battery last while ...
-1
votes
2answers
104 views

How to find voltage across a capacitor?

I was given this problem in a basic engineering circuit analysis class. I really don't know where to start.
0
votes
1answer
31 views

DC Current Density and Voltage in a Finite-Length Conductor

Assume you have a rectangular bar of copper with finite length L. You apply a voltage difference at two points on the top surface of the bar; (x1,y1) and (x2,y2). Because the bar is finite in length,...
0
votes
1answer
31 views

How to calculate voltage of these nodes

How exactly does one calculate the voltage of the marked nodes and arrive at the numbers in the picture (1.75 and 1.628)? I fail when trying. :( simulate this circuit – Schematic created using ...
0
votes
1answer
55 views

How to use Millman's theorem to solve this question:find the voltage value

The question wants me to calculate the Vc simulate this circuit – Schematic created using CircuitLab And here is my thinking: These arrows are the current flowing direction i think,and i ...
2
votes
4answers
210 views

Why should I have the wrong voltage value when I use another way to calculate it?

The question wants to know \$V_{XY}=V_{X}-V_{Y}=X-Y\$ simulate this circuit – Schematic created using CircuitLab The solution said \$I=\frac{10}{15\text{k}\Omega+10\text{k}\Omega+5\text{k}\...
0
votes
1answer
21 views

Voltages and charges with regard to ESD

My question is with reference to this question - ESD protection using a capacitor I am unable to grasp the relation between charge, voltage, and capacitance, although I can understand all these terms ...
0
votes
3answers
104 views

Why is \$A=10V\$, not \$-30V ?\$

Question asks me the voltage of \$V_{AB}\$ and \$V_{CD}\$, \$V_{AB}=A-B\$ and \$V_{CD}=C-D\$, the solution tells me \$V_{AB}=A-B=10-20=-10\$,\$V_{CD}=30+10-20=20\$ I want to ask Why is \$A=10V\$, ...
0
votes
3answers
46 views

Determine the voltage across the 5.0-Ω resistor in the drawing

I have tried to solve this problem but I haven't seen a dc circuit with a battery on the shared portion so I don't know how to include the 2.0 volt battery in the circuit rules. Please help
0
votes
1answer
57 views

If I have a device drawing 300mA @5V and I need to use a 15V PSU what current rating do I need for the PSU?

I have an application with multiple components and multiple voltages in use and current calculations are giving me a headache. A simplified version of my application would include: 1x device ...
-1
votes
2answers
91 views

Design a passive amplifier

I am trying to increase the amplitude of my generated electrical signal by a passive amplifier. I have seen so many complex RLC circuits. But I have limited space for design, therefore, can I use a ...
1
vote
1answer
67 views

Why do some SMPS power supplies require an input voltage select switch?

I have 2 SMPS power supplies near me. One is an ATX power supply, the other is for a 3d printer. They both are rated for 110-240v in, but the ATX supply can handle the full range automatically, while ...
0
votes
0answers
26 views

Using an Audio Signal for a Control Voltage for an Analog Synthesizer

I have a Moog Sub 37 Analog Synthesizer and a Korg SV-1 keyboard. Can I take the audio out of either the line outs or headphone out of the Korg and plug it into the volume or filter Control Voltage (...
2
votes
2answers
101 views

A simple voltage divider problem

I came across a rather simple looking circuit of a voltage divider circuit. It has 5V at one terminal and 0V at the other terminal. Let's start by connecting two 1K resistors in series between these ...
0
votes
0answers
47 views

Output current of LM338T

I tried voltage regulator using LM338T. It is okay to regulate the voltage but when I measured the output current it gives me around 1.5 amperes, not more than that. But datasheet specified it can ...
0
votes
1answer
31 views

For the network shown in the figure, draw the corresponding Thévenin equivalent circuit and establish its parameters VT and RT

I can't find any examples online similar to this format, please help! Attempt: RT = (2*5)/(2+5) = 10/7 = 1.429 k-ohms VT = 8V + 8V = 16 V Do you ignore the center resistor and just add the voltages ...
0
votes
1answer
48 views

3.3v input in a 1.8v logic question

In a board design there's a mistake in the voltage level to control a reset pin (Signal RESETB). It should be 1.8v but it is driven by a 3.3v level. The datasheet shows the next info: It looks like ...
-5
votes
2answers
125 views

Can I use these wires for AC current? [closed]

I bought these wires on amazon, and I noticed in the description that they are rated for 80 volts, and are specifically not to be used for household 110v/220v wiring. However, this wire is basically ...
0
votes
1answer
36 views

Understanding lower voltage’s effects

Let’s say I have a surge protector that has a 15A cable that is rated 1875 watts at 125V. If my voltage is low, let’s say 105V the amount of watts it can supply will drop? So its max safe output ...
-2
votes
8answers
1k views

Why do I need 2 resistors to divide voltage?

I know someone else asked the same question, but I wasn't able to understand it. My question is, why do you need 2 resistors (1 to ground), to divide the voltage? Just 1 resistor would do the same ...
1
vote
2answers
61 views

Calculating total voltage/current for 3-phase?

Consider I have a 3-phase generator with the following measurements: Phase 1 (A): 22.8828A Phase 2 (A): 22.9922A Phase 3 (A): 22.9219A Phase 1 (V): 239.7656V Phase 2 (V): 241.8594V Phase 3 (V): 245....
-1
votes
0answers
28 views

Just not sure - USB/Charging Pad [duplicate]

I have a "wireless" charging pad that is 5v 2a and I can't find a plug that matches the amperage. I have a 5v1a, 6v 800ma, 5v 250ma, and a 5v 500ma, so what can I use to make sure that it's not ...
5
votes
4answers
13k views

Why does current change when adding in an LED?

In the following diagram: The current is 1 mA from: V = IR R = 1 / 1000 = 1 mA However, when I add in an LED with forward voltage 1V: Why does adding in the ...
-1
votes
2answers
80 views

Circuit with a voltmeter across a resistor

Can someone please answer this question? Consider the circuit where the voltmeter read 2.8V across a resistor. Which of these statements is definitely correct? Each electron transfers 2.8J of ...
2
votes
4answers
115 views

Reasoning behind equations in analysis of electrical circuit

I am currently studying the mathematics textbook Nonlinear Dynamics and Chaos by Strogatz. As part of an example, I am provided with the following electrical circuit and accompanying explanation: ...
0
votes
1answer
86 views

How to calculate voltage and current of this circuit?

I already know the answer of question 1, 2 and 3. 1) 448 ohm 2) 1.6 V 3) 0.13 V About the question 4, why 6V/300 = 0.02A = 20mA is wrong? Can I use current divider like 0.01339 * (3.3 * 10^3 / (...
0
votes
3answers
86 views

Finding Node Voltage

I need to find node voltage at A. This seems like a trivial question, but when I set up the resistive voltage divider equations they are not equal to each other. Am I doing something wrong? My ...

1 2 3 4 5 106