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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Voltages to keep my circuit running at 200mA with NMOSFETS

Im trying to build a circuit to send information using IR led, using pulse signals my leds (TSAL6400) operates at 1.35V, and their maximum pulse current is rated 200mA After struggling a bit with ...
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1answer
49 views

Is the P.D across a wire with no resistance always zero?

According to my very basic understanding of Electrical Circuits, the P.D. across a wire with no resistance is sometimes zero. Take this question for example: "If voltage is measured between two ...
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50 views

State of Charge instead of Ah?

My Goal is to monitor the battery's level. My first idea was to build a circuit that would detect its Ah. But I have not come to a solution that is that simple. So I have researched and found out ...
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3answers
71 views

Vpp for American split-phase 110V AC

I know the 'nominal' voltage of 110/115/120 is both based on Vrms and that stability @ any of those levels is pretty much a fairy tail. I also know that most rectifiers will output ~130-150V after ...
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Are all DDR3L (1.35V) DIMMS safe to use in a computer system that uses DDR3 (1.5V) DIMMs? [migrated]

The sales support of (the consumer/prosumer sales subsidiary of) a DRAM manufacturer answered a pre-sales question I made with (translated from an email in French): 1.35V Memory DIMMs are dual ...
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4answers
88 views

Calibrate without a known good voltage source

I'm traveling and don't have a known exact voltage source. I do have a variety of electronic components such as resistors of various flavors and am wondering if there is some kind of trick to getting ...
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0answers
37 views

Can i use lower ampere for devices? [duplicate]

Can i use an adapter 12v2a for 12v4a device? It's for my lcd. It is possible for my to use it? Or there have any kind of adjustment? Does anyone know? I lost my original adapter. Tqvm
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2answers
80 views

5v hydro power generator produces almost 12v

I have this hydropower generator. At its specs it says that it would produce a 5v voltage. So when I have installed this to my water system, and measure it using a tester it says that it produces ...
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2answers
65 views

Multiple resistors to reach needed value?

Im converting an old floodlight to a cree led to run off my solar setup for a yard light I need a 27ohm resistor for a 3.5v 350ma single led to run off 12.5v, but don't have any that value, what ...
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1answer
33 views

Will a 110-220v to 12v converter work with a DC 12v 3w LED bulb? [on hold]

I'm planning to create some wall lights using these LED bulbs. Would I be able to just use any 110-220v to 12v converter to power this at home? I live in the US (120v). I was thinking of using this ...
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2answers
75 views

Why is the collector- emitter voltage (Vce) not getting biased?

This question is an extension for my previously asked question here: Why is the voltage across collector and emitter pushing itself to 0.7 volts? A colleague of mine suggested that I take a look at ...
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28 views

Why output is zero in TIP 31 as CC mode [duplicate]

I am using an Arduino Uno board and R-2R DAC to obtain a signal which should vibrate a transducer connected across R19 of common collector amplifier using TIP31C. I need about 300mA of current to ...
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0answers
44 views

Force voltage, measure current

When using a power supply, they often come with a standalone mode and a FVMI mode. FVMI apparently stands for "force voltage, measure current". What does that exactly mean and how is it different from ...
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0answers
55 views

Why isn't my halogen floor lamp working with new bulb and new dimmer switch? [migrated]

I replaced the bulb and the dimmer switch. There is 120V between the connections when switched on. It varies between 115V on low and 122V on high. The bulb has continuity. I also measured the voltage ...
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1answer
55 views

Output voltage function (circuit-analysis)

What will the function of the output voltage be? My work, and am I right?: ...
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2answers
55 views

Finding Vout of a Transformer

I am a little confused on how to read the ratios of a transformer Suppose there is a ratio of 1:6, is this read as the following? Number of turns on Primary: Number of turns on Secondary? so suppose ...
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1answer
32 views

Battery voltage increasing while measuring (NiMH)

I was going through conditioning for a NiMH battery pack (12 x 1.2V, 1500mAh cell) and decided to check the cell voltages. I noticed that the measured voltage, with a multimeter, increased over time. ...
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3answers
60 views

Powering and operating dual electric linear actuators

I am in the process of building a height-adjusting desk. I am pretty good with computers (I'm a programmer), but I never learned much in the way of electrical engineering. I recently purchased two ...
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7answers
1k views

Does ground suffer from a voltage drop like effect?

I am currently working on a project where I need some very long wires (about 20 meters, and that is 40 meters both ways), that will be connected to a button which will be used to trigger a pin on the ...
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1answer
24 views

alarm with reed and relay switch with memory [closed]

My teacher recently assigned a circuit for us to build on the breadboard; it has to include a relay, a button, and a reed switch. When the magnet is removed from the reed switch, the alarm would ...
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1answer
66 views

Splitting AC voltage based on phase

Is it possible to separate the positive and negative portions of an AC voltage wave into two separate lines, where one line has the positive voltage portion (and is neutral when the source is ...
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0answers
20 views

Solving for a voltage using KCL w/ multiple current sources

I'm solving for Vds(s). I'm somewhat unsure about how to write the KCL equations for this circuit. Shouldn't Vds(s) be equal to the current provided by the dependent current source on the same branch ...
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Got shocked by a native dell laptop charger outputting 19.5 V 6.5 A DC. It was REALLY uncomfortable, but was that dangerous? [migrated]

Okay. My laptop was running out of battery. I grabbed my charger (outputting 19.5 V 6.5 A DC) which was plugged into the wall, and as I touched the end of the charger I got some electric shock going ...
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1answer
81 views

Why is the voltage across collector and emitter pushing itself to 0.7 volts?

I designed a single stage transistor amplifier as shown in this schematic: I constructed this on a breadboard and applied the DC bias voltage to check the biasing conditions. Prior to this, I made ...
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1answer
30 views

Essential Nodes in a Circuit

My book says above that there are three essential nodes in the circuit above. I am seeing four essential nodes in total which are marked by those four black dots. Since each of those black dots ...
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4answers
196 views

converting 3.3v to 1.2v

I have a electrical problem that I hope to get some help with. Let me first start of by saying that I'm quite a noob in this field (I'm a IT guy), but I hope to learn something. The problem I have is ...
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1answer
451 views

Why can people touch high voltage?

So I know that you need a certain current flowing through you to die, I've heard from some people "its the amps that kills you", and from others "Its the volts that drive the amps" and I realize ...
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1answer
60 views

Testing voltage continuity using a beeper?

I have a 48v rail and i wish to plug it into an audible oscillator to check for continuity when i am rattling the system under duress. What is the simplest circuit that i can plug into 48v to hear the ...
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3answers
89 views

A conceptual question about voltage multipliers

Imagine a micro-controller's pulse output is coupled to a voltage multiplier with many stages such as in the case of a Dickson voltage multiplier. We then can increase the DC "voltage" level of the ...
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1answer
31 views

Would having a DC-to-DC Step Up Converter Damage the L293D H-bridge IC behind it?

I recently purchased two L293D H-bridge Motor Controller from Adafruit (data sheet here), but after reading that the controller could only output a max of 600mA for a short time, I realized I had a ...
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3answers
114 views

How to turn a 200~Khz AC voltage into a proportional DC voltage that does not exceed 3.3V

now, I have an induction heater, which runs at 200 Khz, and near the coil of the induction heater is another coil, now, if they coil is near the IH's output, currents will be induced into it, yes? ...
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47 views

Simple DC ramp up circuit

I am after a simple circuit that ramps from 0 to VCC relatively linear over a few seconds and ramps down only when power is removed for around the same time. I have been advised an RC circuit may be ...
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2answers
82 views

Currents when converting voltages down

Okay, so I have what could be considered a silly question I should've probably learned when I started working electronics way back when, but I just now thought of it and haven't really needed to ask ...
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1answer
52 views

increasing the battery amps to fit a water pump [closed]

I have a battery of 12V(yuasa YB3L-B), 0.036 Ampere, and a water pump(SEAFLO bilge pump), running on 12V, 1.8 Ampere. How can I increase the amps of the battery to fit with the pump?
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1answer
69 views

What does 'g' in switching converter input voltage \$V_g\$ stand for?

I'm studying switching converters and the input voltage of a Buck, Boost, or whatever is designated as \$V_g\$. I've racked my brain (and also searched Google), but I can't work out what the 'g' could ...
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3answers
48 views

checking voltage range without a fixed reference voltage

I am trying to come up with a circuit to determine if my power supply voltage is within a specific range. For example, my nominal voltage is 3.3V but I want to make sure that the lowest voltage that I ...
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current or voltage what is imp to run a load [duplicate]

recently i took a power supply fan which says 12 V and maybe 0.15 A to run.So which is the priority that i should follow to make it run should i go for 12 v supply or should i go for 0.15 A secondly ...
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1answer
51 views

How can I derive a voltage equivalent without affecting the output?

In the above schematics, I want to make the equivalent of the circuit on the left side. What I mean is I want to derive V2 from V1 and get rid of using two supplies. I want to derive V2 from V1 by ...
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2answers
46 views

Finding relevant voltages and current in a BJT

I'm supposed to find Vb, Ve, Ic, Vc and Vce for this circuit but I have never seen anything like this, so I'm lost on how to even approach it. Do I start from KVL and write two loops? But then ...
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3answers
43 views

Generate Power off of several motors at once

So in working on a project, I am considering generating power using several small 12V motors (made for DIY toy cars, very cheap on amazon) or by using one bigger electric scooter motor (24V, 250W, ...
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2answers
78 views

Few questions about basic concepts in electronics

So I'm rather new to electronics and I'm struggling to understand some basic concepts because I picked up little information from many different sources so it's starting to get confusing :/ Why does ...
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2answers
805 views

Can I use a 5V phone charger to run a device which expects 3.7V battery power?

I have an old mp3 player which originally ran from a 3.7V LiPo battery. It could be charged from USB using a mini-usb connector. The device goes into charging mode when power is present at the usb ...
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1answer
210 views

Why does this zener diode fix the voltage to the LEDs?

I am just getting started working with small electronics. I have soldered together a few kits and recently converted a car stereo into a home stereo. With all of this soldering, I found this ...
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3answers
81 views

Confusion around common mode voltage

I understand the basics behind the concept of common mode voltage and CMRR and friends, in the context of differential amplification. What I don't understand is the determining if the whole concept ...
0
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2answers
31 views

The role of internal voltage source resistance in pulsed operation

I have a question regarding the role of the internal voltage source resistance in pulsed vs DC operation. Here is a sketch of the situation I imagine: simulate this circuit – Schematic ...
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4answers
673 views

What is the difference in meaning of a voltage signal and current signal?

This might sound like a crazy bad question. But I'm wondering even though current and voltage inevitability co-exist, why do we use the term for one concept(current or voltage)? If there is a signal ...
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How to calculate voltage between point P and Q?

I have 2 wires and I need to calculate voltage between 2 points P and Q (see image). I would use this formula: Phi(PQ) = Phi (P) - Phi (Q) = Tau/((2*pi)*(epsilon0)) * ln (r(P1)*r(Q2)/r(P2)*r(Q1)) ...
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1answer
54 views

Determining voltage requirement of unknown circuit board

I have a vintage, home-built metal detector from the 50's/60's with a simple circuit board. It apparently had a home-built battery pack that plugged in but it is now missing (9-volt battery style ...
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35 views

Voltage converter circuit

Please help I need a voltage converter (blue box) for this circuit. IG1 (battery voltage 0~16V) given the ON and OFF threshold voltage will convert it to Power IC enable/disable port (ON: 2V or more , ...
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5answers
120 views

Why does a resistor reduce voltage if V=IR? [duplicate]

I'm sure this is a very simple question, but I have been confused about this topic for a while now. According to Ohm's law, resistance varies directly with voltage. This means that if resistance ...