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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).

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LiPo ballancing circuit

I'm designing a circuit board to which I'll be able to connect multiple LiPo batteries (2-6S) and charge them in parallel without bothering user about balancing those packs firstly. So the charging ...
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2answers
50 views

Preventing overvoltage on serial pin

I am trying to send data through serial from a 3.3v Arduino to a 5v Arduino. I assume I can't just connect the 3.3v tx to the 5v rx because, when I program the 5v one I am assuming it will send 5v ...
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64 views

MAX485 controlling output voltage

I'm trying to use a MAX485 module to interface a RS-485 domotic bus, when I use the oscilloscope I see that the original bus signals (A and B) are between 1.9 V high and -2.250 V low (4.15 V amplitude,...
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2answers
105 views

0-3.3V to 0-5V step by step [closed]

I have a 3.3V microcontroller. I want to use dac. I will work 0-5V range. But my microcontroller has max voltage 3.3v. I want to use a amplifier. I wait your recommendation. note: how can i this. ...
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1answer
80 views

Does a capacitor return the voltage you give it or the voltage specific to the capacitor? [closed]

I bought a 'Juice jw2d 2.4 farad 24V surge low esr' capacitor. It's a type of capacitor used for car audio sound systems, 12v I assume. I however need to use it for a 24v sound system. Does '24V ...
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34 views

What will be the output voltage if I supply 1.5V to a 3V to 32V XL6009E1 voltage booster? [closed]

Basically I need to convert 1.5V DC to 12V DC. If the module mentioned above fails to do the job,then what should I use instead. Is there any way that I can add two voltage sources in series and then ...
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2answers
43 views

Determine efficiency, voltage, current from motor characteristic curves

I would to identify efficiency, voltage, current for a particular Brush less DC motor in our lab given characteristic curves. Electrical specifications are The operating conditions are ...
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3answers
154 views

What do we mean when we say a transistor amplifies current? [closed]

No site, seems to explain this super well. For example, if current amplifies current then shouldn’t there be a larger voltage drop after, the current, per se, is amplified by 100? But the voltage drop ...
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1answer
34 views

Why the Base of T2 gets no more voltage if S1 is opened?

When S1 is closed, T2 no longer gets enough voltage to switch. Obviously it is because the capacitor is being discharged when S1 is opened, but what actually happens at the base of T2 when S1 is ...
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1answer
50 views

Trying to come up with a overvoltage overcurrent reverse polarity protection circuit, is option 3 done right?

I´m reading for the past week about P-Channel mosfet reverse polarity protection circuits. Then I´ve found this post http://kaktuscircuits.blogspot.com/2014/07/reverse-polarity-and-overvoltage.html ...
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1answer
107 views

Confusion about current flow

I'm trying to understand how the charging of a plate capacitor works which lead me to question my understanding of current flow. In many explanations, it is said that the voltage source pulls the ...
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9answers
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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 ...
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1answer
85 views

48VDC safety precautions?

I am building a bit of equipment that requires 48DVC @ 2.5A to be brought out of the metal box housing it. I intend to feed it through a piece of plastic tubing along with a sensor wire, which exits ...
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2answers
63 views

What does “heavily decoupled voltage source” mean in this context?

Regarding the following paragraph: To measure the amount of input-referred noise, the input of the ADC is either grounded or connected to a heavily decoupled voltage source, and a large number ...
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1answer
112 views

Large blue arc from capacitor when shorting it - how deadly was this situation and how much energy was inside?

I was working on a transient circuit and I applied a 8kV, 2 ohm voltage transient on its input with a rise time of 10us and fall time of 50-100uS. It comes from a transient generator off mains so can ...
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1answer
51 views

Switch array (crosspoint) and DC biasing of audio signal

For a project at my university, I am making a guitar effects switcher. Guitar effects work on instrument level audio signal which is AC only. I plan to use ADG2128 analog switch array (https://www....
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3answers
132 views

What does voltage really do?

I know there are many videos (many of which I have watched) and many posts (many of which I have read) about voltage, but I feel like a few points are left out that should be explained. What is ...
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Peltier behaves strangely

I've been trying to test my Peltier moodule (tec1-12706) with 2 1.3V batteries (2.6 in total in series) connected parallel to the module.. ...
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3answers
104 views

Are things powered by the amount of joules (energy) in a coloumb or by the amount of joules (energy) flowing every second? [closed]

My question is in the title, Are components powered by Volts or Joules? I believe it is joules/coloumb, right? Because, if things are powered by Joules/Second then that would mean that the current ...
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4answers
128 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 ...
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2answers
72 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 ...
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3answers
68 views

Controling Mosfet by 3,3V Raspberry Pi GPIO Pin

So I'm currently working on a project where I need an IR camera with two IR Leds attached to it. The camera looks something like this: https://rads.stackoverflow.com/amzn/click/com/B01ICLLOZ8 These ...
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2answers
145 views

What is the current when there are no resistors?

How come I always see videos with what seems like a random amount of mA flowing from a battery with a certain amount of voltage? For example, what if a wire had 0.13 ohms resistance and a battery had ...
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1answer
27 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 ...
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2answers
39 views

Transformer and Thevenin Theorem

Consider an ideal transformer connected to a real AC voltage source (with output resistance Rg). Now consider to apply the Thevenin theorem between the output terminals of the secondary circuit. I ...
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1answer
88 views

voltage drop calculations single phase ac

In voltage drop calculations, in one of the methods in case of single phase ac, the formula is given as follows As you can see, R is resistance per unit length multiplied by length by current and ...
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1answer
29 views

protection board for 18650, voltage drop? normal?

I made a power pack using 18650 batteries from an old laptop. All batteries tested individually are good. 4 batteries in 2S format. I used a cheap 2S 3Amp rated protection board I got on Ebay from ...
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47 views

How to get output of 12V from a 15V output without dropping the current

I am planning on using NI myDaq to power a motor and encoder which requires 12V, but myDaq outputs 15V. How can I reduce the voltage to 12V without dropping the current? I was planning on using a ...
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2answers
71 views

MCP1703 quiescent current is very high

I want to use the MCP1703 regulator in battery powered projects. The datasheet of this regulator says that the quiescent current is typical 2 uA. I measured the quiescent current for the MCP1703-5 ...
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1answer
85 views

Does wiring 18650 batteries in parallel and/or series increase the discharge rate of the whole pack?

I cannot seem to find a solid conclusive answer anywhere on this, but if I build a pack of 6 18650 batteries in parallel which are 3500 mAh each, that would make the pack 21 Ah in total. Then I take ...
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2answers
1k views

Estimate capacitor parameters

I am thinking of making a capacitor, just for fun/for studying purposes. And I thought of the following exercise. In my local store, there exists rolls of polyethylene food film and aluminium foil. ...
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2answers
87 views

Crockcroft-Walton Voltage Multiplier Large Voltage Loss

I have a CW voltage multiplier that uses 30kV, 1nF capacitors and doubled 20kV, 5mA, 100ns diodes (for a total of 40kV). My ac source is a sine wave (viewed on the primary side of the transformer ...
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2answers
40 views

Compensating voltage drop in circuit

My brain seems to be stuck on this very basic circuit design question. I want to power a 24VAC load (solenoid valve) with the help of a switch (triac). This switch, however, creates a voltage drop of ...
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1answer
55 views

How does the output jump up to 7.5 volts when the switch is closed and opened again?

Sorry if the question might sound dumb. In this circuit, when the switch is closed the output voltage drops to zero and then rapidly charges back up to 5 volts. My question being, when the switch is ...
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2answers
67 views

Impedance matching and reflection

I have a simple question about reflection and impedance matching. Consider a voltage generator Vg with its output impedance Zg, and suppose it drives a load Zl. In order not to have reflection, we ...
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4answers
122 views

Voltage transmission

For the sake of understanding, I shall refer to voltage as a "pushing force that causes electrons to move and hence generate current." Now, I know that this force is "built up" and does not flow(...
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2answers
26 views

Resultant voltage function through two opposing coils with mutual inductance

So my question is about the type of relationship in a particular circuit. I would like to know if it is linear or something else like a power. The circuit in question is a pair of adjacent, mutually ...
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5answers
133 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. ...
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Low range of voltage from a potentiometer connected to Toolstick card Silicon Labs

I have a linear potentiometer of 10k ohms which I connected to a toolstick Card (a microcontroller distributed by Silicon Labs). I used the ADC of the card to convert the analog voltage to digital ...
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2answers
132 views

Different voltage sources in parallel

I realize connecting two different voltage sources in parallel is a contradiction (in an ideal circuit). But if I were to connect this in practice and measure the voltage across points A and B, what ...
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0answers
42 views

Arduino receiving correct audio data from analog input?

I've connected my arduino's analog input to my phone's headphone jack and am trying to visualize the audio data in the serial monitor. I have read on Arduino's site that the Arduino UNO is able to <...
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1answer
78 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). ...
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1answer
50 views

Successive approximation conversion

Can someone explain me from the following table on how to get the DAC output.
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2answers
117 views

Battery operation, charge and discharge processes misconceptions

I'm trying to elaborate a simple explanation (and conceptually correct) of how a battery charges and discharges, and why we say things like "the charge stored in the battery is x Ah". For now, I have ...
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2answers
133 views

Voltage drop on some PCBs, but not all?

I'm pretty inexperienced at electronics (but learning!) and recently had some PCBs manufactured for a project I'm working on. I had 40 PCBs made (PCB Assembly done by the manufacturer) and received ...
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3answers
82 views

Convert from a specific voltage range to another

I need to convert the external control voltages of +4/-4V range to 0/5V in order to replace now obsolete SSM2050 with micro controller based solution inside an old vintage synth. Is there any easy and ...
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2answers
61 views

Voltage drop and voltage dividers

First, I'm not interested in numbers or the general math behind this. I know how to split voltage into some particular value(s). But what is actually going on? I get Kirchoff's Voltage Law, or at ...
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2answers
71 views

Parallel circuit with LED on one path and resistor on the other

I'm a beginner to circuits. Unlike many other questions, my circuit involves a parallel circuit with a LED on one path but a resistor on the other, as shown in the picture. Q1: assuming the LED has ...
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1answer
61 views

Wiring a Logitech extreme 3D pro joystick for Xbox adaptive controller

The joystick only allows direction movement when connected to the Xbox adaptive controller, which doesn’t help when I have 1 hand and 17 buttons to connect. There are only 10 buttons of the joystick ...
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1answer
39 views

Voltage rating on panel jack

I'm building a power converter that will take 20 VDC input. I have a cable with a 1.7 x 4.0 mm plug, so I'm trying to find a suitable panel mount jack. Online, I've found this model. On the Philmore ...