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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What is the formula for the maximum permissible symmetrical input signal swing?

I have a common-source amplifier, and I am looking for the maximum no- load symmetrical output signal swing, and maximum permissible symmetrical input signal swing. I would like to know the formula ...
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30 views

Directly Power STM32 from Lithium Battery

I'm putting together a wireless sensor node and it's running a STM32L051 which can run at a 1.65-3.6v range. I've also got an RFM69HW radio onboard which can run at 1.8-3.6 (2.4-3.6 for full power ...
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10 views

Current and voltage from PV ( LTS25NP , LV 25-P)

So in my design I am going to sense two PV panels in series ( Both voltage and current) to extract the Maximum power point (MPPT by arduino) so the input of both sensors will be the PV output and the ...
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2answers
50 views

Question about this RC circuit and voltage across the capacitor

I just have a small question about the below problem. How did they get Vc of the capacitor to be 12 V before the switch is opened? Doesn't the resistor use up some of the voltage?
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1answer
75 views

Is it ok to use voltage dividers instead of voltage regulators when adjusting reference voltages for opAmps?

My question is about manually adjustable circuits with a knob, coarse ect. When adjusting reference voltage of an opamp, for instance, trigger level of a schmitt trigger or gain of an amplifier ...
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79 views

Strange LED behaviour

simulate this circuit – Schematic created using CircuitLab I have +9v connected via 180 ohm resistor to the collector of an NPN transistor. The emitter is connected via 680 ohm resistor ...
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1answer
39 views

Maintaining DC voltage with more batteries

I have a circuit which i am powering with two 1.5V AA batteries that dies at 2.6V volt as the battery discharges. Reading around, i realized that even though there is energy in the batteries, my ...
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16 views

Square wave oscillator (up to 5kHz) from -40V to -10V (approximately)

I want to test a depletion mode TFT which has a turn on gate voltage of about -35V and consequently I want to show that this TFT can be used as an inverter and find the maximum frequency at which it ...
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22 views

Connect the output of an Arduino to the input from another Arduino [migrated]

I'm making a project and i'm trying to send bits from an Arduino to another Arduino with the digital pins. So my setup are 2 Arduino's connected with a jumper. I connected the grounds and they have ...
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1answer
49 views

Running a 7v shift register from arduino 3.3v

Im trying to learn some electronics, so im not that confident with some of these systems, I recently bought a load of the alphanumeric displays from Sparkfun but foolishly read the data sheet for ...
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1answer
33 views

Artix - 7 Voltage Specification I/O standard

I want to design a PCB for FPGA prototyping. Please help me understand if I need to supply these voltages and why? Vref Vrefp Vin These voltages are from the Artix-7 Datasheet. ...
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1answer
44 views

what is the waveform difference between primary and secondary of transformer

I am talking about the autotransfomer. I am wondering how would the waveform be different is if I measure the Voltage at primary side, versus measuring voltage at secondary side. Is the general ...
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1answer
40 views

Trouble calculating time to drain a capacitor

Introduction I'm having trouble producing an equation that involving my MAX756 boost chip, a load and my 1.5F capacitor. Basically I'm trying to find out how long it would take for a 1.5F capacitor ...
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1answer
43 views

Need help with gaining some basic intuition regarding transmission line traveling weaves?

I always thought about current traveling through a wire much the same way marvels would travel inside a hula-hoop (all moving at the same time from one end to the other). In this simple scenario, ...
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2answers
127 views

Why are flat copper cables with holes used for high voltage ground?

I saw that a flat copper cable was used for the ground connection in a high voltage lab. I was wondering whats the difference as opposed to a normal cable ?
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2answers
81 views

Are there any high voltage (14V) MCUs? [on hold]

Switching regulators and LDOs are not an option, for complex reasons. Are there any MCUs which can tolerate a 14V supply voltage? I'm currently looking at 4000 series logic to do what I need, but I ...
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1answer
43 views

Voltage between two points of a square contour in a magnetic field

a,d,R is given. Current of infinitely long wire is \$ i(t)=I \cos(\omega t) \$ I get the flux derive it over time what to do with R? The solution in the book is: ...
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3answers
976 views

Can a diode effectively regulate a supply voltage?

I have a 6V DC battery that's rated at 2A. My microcontroller uses 5V supply at about 50 mA. I've been told I shouldn't worry about the current since the microcontroller will just take what it needs. ...
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2answers
63 views

How to read datasheets for TTL logic gates regarding maximum output current conditions [duplicate]

From what I have been reading, the input stages to BJT TTL logic gates are emitter terminals of transistors. As such, when the input to these gates is logic low the base-emitter junction of these ...
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729 views

How is it possible for voltage to exist when only a single voltage source terminal is connected?

Please take a moment to look over the circuti below: As you can see, the circuit is nothing more than a 10 volt power supply and a diode. Note that the power supply negative terminal and the diode ...
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17 views

Where can I find the ac voltage in this diagram in LTSPICE software?

Where can I find the ac voltage in this diagram in LTSPICE software? Secondly, which settings in this software do I have to make to get alternating INPUT voltage just like in the diagram? What ...
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1answer
38 views

Using a diode to lower supply voltage to nrf24l01+?

I was wondering if I could use a IN40007 diode (or Zener diode) instead of a 3.3V voltage regulator. I plan to power the module using a 3.7V LiPo. Since the battery would be 4.2V when fully charged, ...
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9 views

Using WeMo controller with AC that uses 6-15p plug [closed]

I have an older A/C unit that uses a 6-15p plug. I want to be able to remotely control the unit with a WeMo, but it uses a 5-15r receptacle and plug. The A/C unit says its rated for 208V, and I ...
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2answers
34 views

Can I use an open-drain NXP 74LVC07A output as level translator for an 8V CMOS input?

I'm designing circuitry that uses an NXP 74HC4051 analog mux with a +8V supply. An MCU with 3.3V GPIOs needs to control the mux S0-S2 selection inputs. I am wondering whether an NXP 74LVC07A, powered ...
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1answer
92 views

Shut off circuit when under a certain voltage?

I have three batteries wired in series, in order to produce 9v. If one of those batteries dies, I need the whole circuit to shut off. The best solution I've found is to use a comparator, but the ...
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3answers
91 views

How can this circuit read a value for amps at 0 volts

I made a simple circuit using this: It can tell you the voltage and current along a wire if you mouse over it. The wire down the bottom reads 4.55mA and 0V (the little yellow dots actually move to ...
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4answers
170 views

How do I explain current and voltage to a lay man?

A man asked me this question in suburban train when I told him that I am an electrical engineer. Of course I replied him that current is the flow of electrons and in order for the current to flow ...
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1answer
46 views

If I have three button cells in series, and one of them dies, will the whole circuit still function at a lower voltage or will it stop flowing?

If I wire three button cell batteries in series, their voltages should be summed. Now, if a battery dies, let's say BAT3 for the sake of example, will the circuit ...
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2answers
228 views

Cascading voltage regs not working as expected

I was trying to hack together a power supply circuit with bits I had lying around but I didn't get the voltages I thought I would get, this is what I naively thought would happen: But in reality ...
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1answer
43 views

USB datalogger ground read isn't zero volts

Im using NI DAQ USB 6008 datalogger. When I connect A0 (or 1,2 etc..) to ground in single-ended mode it gives 6 mV. Shouldn't it be 0 mV? Is it corrupted or normal?
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147 views

How would I convert a 4.1(ish) volt li ion battery to 240v ac?

I'm fairly interested in electronics but not very educated in it. I was wondering how I would go about safely converting your average li ion battery pack to a usuable voltage (240v ac) for things ...
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4 views

Operate Arduino Nano using variable voltage [migrated]

How safe/dangerous is it to operate an Arduino Nano 5V with a varying voltage source? I have a circuit that provides a duration of power with a starting voltage of 5.3V and an ending voltage of 4.5V. ...
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59 views

Replacing a relay by a transistor

i'm new in electronic, I made a simple circuit to control a pump it's working, but i'm really not happy of the result. I have to plug 2 power sources because if I have only one for the pump and the ...
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1answer
42 views

MP3-25 flexible solar panel providing low current

I am working on a project where I need about 20 mA to come from a particular solar panel I am in possession of. The solar panel is an MP3-25 panel, I actually have 2 which I am trying to get to work. ...
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1answer
98 views

Using a MOSFET to switch a High Voltage on a Capacitive Load

I am trying to bias the filament of an electron gun to -575 V, but I need to switch it on and off using a TTL signal. I have an idea for how to do it, but I would like to know if it will work before I ...
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3answers
350 views

PSU Current on negative line

While i am quite familiar with most of the specifications on a power supply unit like this one, I fail to understand what is going on with the negative voltages. I have a few theories, though. ...
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0answers
188 views

Positioning of a resistor [migrated]

Apologies in advance, my electronics knowledge is very poor. I've got myself a resistor that I believe is appropriate for the job I want to do on my vehicle. I'm replacing the factory sensor; there ...
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1answer
48 views

How does open circuit voltage work?

So supposedly there is a potential difference between those two rods when the circuit is open. Does this mean theres an electric field present here such that ∫Edl≠0 ? If I put some random loop of ...
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1answer
136 views

Weird voltage measurements on transistor

Just as an experiment, I decided to put together the following "circuit": I then went ahead and measured Vbe, Vbc and Vec and this yielded the following results: Vbe = 0.602 V Vbc = 0.589 V Vec ...
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3answers
46 views

Voltage range of a differential pressure sensor px26, and opamp saturation

Im using a px26 001GV differential pressure sensor for a project with arduino, here is the data sheet. (http://www.omega.com/manuals/manualpdf/M1608.pdf) Now, I have few questions regarding this. 1) ...
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1answer
51 views

Capacitor discharging dilemma!

Let us take a capacitor charged by a source voltage of 12 V d.c. supply. Having fully charged, the capacitor is now connected with a source voltage of 5 V d.c. supply. What will happen to the ...
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2answers
65 views

What is a dead battery cell, what causes this to happen, and what are the implications?

Today I had a bit of car trouble where the culprit turned out to be the battery. I had driven my car just 5 minutes earlier without issue, but upon attempting to crank the vehicle it made a final ...
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63 views

Why is the voltage over this dependent voltage source not zero?

I have the circuit shown below. I need to find the Thevenin voltage for it. If the dependent voltage source was a resistor instead, I think I could have disregarded it when using KVL (since the ...
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0answers
12 views

how to hardwire a car.(dashcam) [migrated]

video where i check all my fuses: https://www.youtube.com/watch?v=74YimFvXEsQ fuses that lighted up without key: 11 Moonroof (20a) 12 accessory power socket (with idk why it did since it doesnt ...
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74 views

Making LEDs switch on at certain voltages as indicators

Is it possible to have a simple circuit that turns one colour of a two-colour LED on at one voltage and then the second colour on at a higher voltage. My concern is that if I size a resistor for each, ...
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1answer
40 views

Voltage source connected to a MOSFET source

This circuit simulate this circuit – Schematic created using CircuitLab where M1 is an n-channel MOSFET, is said to be incorrect. If the voltage Vin should be imposed to the source ...
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3answers
120 views

Whats the effect on Voltage and Amps when 244 9v batteries are connected in a series?

There are many opinions about a stunt a guy did on youtube, where he connected 244 9v batteries together in series. Can someone clarify the magnitude of Current being limited by the chemical ...
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1answer
75 views

Non-zero output from a LM741 in a differential configuration

I'm trying to amplify a DC voltage coming from a strain cell (with a built in Wheatstone bridge). The voltage swings from -1mV to about 4mV depending on the strain. I've set up a differential ...
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1answer
33 views

having different voltages from 2 batteries in serie (3 voltages…)

for a project, running on battery, I need 3 different voltages (+/-3V and 6V) +/-3V for OpAmp and µC (attiny85 will be plug to the 3v) 6V for the actuator I was thinking about using 2x CR123 (3V ...
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53 views

How to charge lithium-titanate battery with lower voltage

I would like to charge a lithium-titanate battery rated at 2.4V (capacity 50mah, max charge voltage 2.75V), which is lower than the typical li-ion battery (3.7/4.2V). Most charger ics seem to be ...