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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4answers
52 views

Converting voltages using LM337

I have 2 questions: Is it possible to generate -35V from LM337 regulator with -12V in input?? The voltage output from LM337 is supposed to follow this equation, -Vout=-1.25(1+R2/R1)+Iadj.R2 but in ...
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2answers
91 views

Voltage Regulator Not Providing Enough Current/Voltage

I am attempting to deliver 9V @ 1.1A to a PCB circuit design using an L7809CV voltage regulator which is rated for 1.5A max. Using a power supply, I can deliver the required current and voltage to my ...
0
votes
1answer
33 views

Find the maximum of three sinusoidal voltages at any point?

Given three sinusoidal input voltages, I need to design a circuit to output the highest voltage, without using opamps. I honestly have no idea where to start, so would just appreciate any hints or ...
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0answers
25 views

Artificial Lightning [on hold]

I am planning to create artificial lightning from home electricity (240V AC).In order to do that I need to have two balls, one with positive and one with negative charge with high potential difference ...
2
votes
1answer
49 views

Can I use a voltage divider for shifing logic levels?

I'm trying to drive a 3.3V IC from an Arduino which has 5V logic pins, so I need to shift that 5V down. There's no data from the 3.3V device to the Arduino so I don't need to shift back up. Can I use ...
0
votes
1answer
36 views

Find the base potential

Question "a" says "find the base potential Vb", and I can't do it :(. All the resistors are given above (you don't need to understand french, don't worry) Could someone help me please, I would ...
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votes
3answers
85 views

Physics circuit analysis question [on hold]

How would I calculate the voltage drop across the 60 ohm resistor without knowing the voltage? also, would the total circuit resistance be 7.74 ohms?
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votes
0answers
43 views

Pressure sensor voltage climbs then drops steadily with increased pressure

I have a few pressure sensors on a high pressure (3000 psi) system powered with 5V DC. These sensors are three wire type sensors but I don't know much more than that. Some documentation indicates ...
0
votes
1answer
48 views

Behavior of power supply and DC motor for voltage/current combinations?

Are the below statements correct? Marked in Bold and Italic are my doubts! Unregulated power supply (Battery?) If supply current rating > motor current rating --> No problem since motor pulls only ...
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0answers
52 views

convert [-24V,24V] range to [0V,3.3V] range

I need to realise a circuit that converts an analog signal from [-24V,24V] to [0V,3.3V] before sending that signal to an ADC "MCP3208", I found the circuit in the picture above,it works perfectly in ...
0
votes
1answer
59 views

A switch that is only ON if the reference voltage is matched -+ 0.1 volts

Im a beginnerish will electronic and im looking for a switch that is only ON if the reference voltage is matched -+ 0.25 volts. So if i have a reference of 2.7v to match and i feed the switch a 2.75v ...
1
vote
1answer
77 views

Does +12V to -12V = 24V?

If a battery gives me a 5V terminal and a 0V terminal I calculate power by multiplying total current of the circuit by 5V. What if the battery has a +12V and -12V terminal I'm using to power my ...
1
vote
1answer
51 views

How do I calculate Watts for a dual rail power supply?

If I have a 5V power supply powering a circuit which is connected to 0V, to calculate power usage I would take the total current in Amps and multiply by 5V. However, my current circuit uses -12V, ...
4
votes
1answer
104 views

What's an efficient way to get below the standard 1.25V on buck converters?

So, I purchased a buck converter which was advertised to be able to range down to 0.8V but, as you can probably guess, it only goes down to 1.25V which I understand is the reference voltage for the ...
0
votes
1answer
49 views

Controlling high voltage PWM [on hold]

I want to use Arduino(or others) digital pins with PWM to get below outputs. Voltage 0-50V, Pulse amplitude: 0-100mA, Pulse width: 0-200us, Frequency: 0-1kHz I need your help and suggestions for ...
0
votes
1answer
26 views

Stepper motor voltage rating

I want to drive a stepper motor which I've extracted from an old Epson printer. I am able to recognize that the motor is bipolar and i found the coil polarity by testing it with a multimeter. However ...
0
votes
3answers
147 views

I can't understand the logic with power = voltage * current

I mean, if I have a 2000W device and plug it in a 220V outlet, it will produce about 9,1A. But if somehow the outlet is not delivering 220v, but less, like 180V, according to the equation, it will ...
3
votes
3answers
751 views

Why put a voltage divider between a battery and the battery pin of an RTC?

I bought a PCB module including a DS1307 real-time clock to evaluate if that RTC is right for the system I'm designing. Here's part of the schematic: The DS1307 works with a battery voltage ...
-5
votes
0answers
32 views

Increase Motor Speed By low Voltage (AC) [closed]

i want ask question How i can increase motor speed AC not DC ? IF i set arm from this arrange motor , gar , arm . this arm will increase this speed . if yes what is relations with it and speed ...
0
votes
2answers
62 views

How do I stop/compensate for a voltage drop across a transistor? [closed]

I have used a 555 timer to output a pulsed signal with amplitude 4.6V. I am then inputting this signal into a transistor to pulse an led. When I do this the amplitude drops to 0.8V. How can I stop ...
0
votes
1answer
50 views

Voltage Conversion Module

So firstly i'd like to say I'm relatively new with electrical engineering, nothing more than backyard experience. However I am a computer programmer so I can grasp the concepts fairly well. One of ...
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votes
2answers
37 views

2 state converter, from -24VDC [ON] - +5VDC [OFF] to 5VDC [ON] - 0VDC [OFF]

So as the header says, I would like to take a 2 state signal (ON/OFF) where the on state is -24VDC and it's off state is +5VDC and make that/convert to a 0-5VDC 2 state signal, where 0 is the ...
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votes
7answers
2k views

Why to disconnect the negative/ground terminal, not positive?

To break off any circuit, the common way is to disconnect the negative and or ground terminal. I rarely see people disconnecting the positive and if so, they're not well educated in electrical ...
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votes
2answers
47 views

Solar Panel not charging battery? [closed]

​i have a solar panel of 12V and i want to connect with 12 volt battery through charge controller than pv show different values like 12.6 , 11.1 , 10.5 , 9.6 ... so i am fully confused, please tell me ...
0
votes
1answer
73 views

plugged 240v into 110v amplifer - is this repairable? [closed]

I imported a 200w mono subwoofer amplifer from the US and stupidly misread the 250v fuse rating as the input voltage. Plugged it in into my UK 240v supply and the slow-blow fuse blew. I have since ...
0
votes
1answer
46 views

Node voltage analysis on circuit with a dependant voltage source

I am carrying out node voltage analysis on a circuit that has 2 voltage sources. One source is independent The other is dependent on a current through a resistor in the circuit After i carry out ...
-4
votes
1answer
42 views

How to know the voltages between inductors? [closed]

I've got a schematic as below, but I don't know what voltage is a output. simulate this circuit – Schematic created using CircuitLab
-1
votes
0answers
67 views

voltage amplifier stage for audio

Are there any blaring reasons for why this voltage gain stage wouldn't work? Or anything that can obviously be improved upon? I don't currently have a current mirror to bias the bases of the voltage ...
0
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0answers
8 views

ADE7754 irms value

i am using ADE7754 to measure 3 phase voltage and current. I am able to read voltage values, but not the current. Micro-controller that i am using is ATSAMD20e18. Can anyone help me out with this ...
-1
votes
1answer
67 views

Human (myself) being a magnet for dust and hairs entering my eyes from anelectric shaver or a room [closed]

My name is Tony and I have a significant problem. Each time I shave, no matter what precautions I am taking, such as wearing goggles to shield my eyes, I get cut facial hair not fall to the floor but ...
0
votes
1answer
26 views

How to prevent output voltage spikes

My vaping device operates in two modes, variable temperature control (VT) and variable wattage (WT). The unit first sends out a ~1 second 30 watt/7.74 volt surge to the coil to see which mode it ...
1
vote
3answers
82 views

Increasing sensitivity for voltage measurement

I am trying to differentiate between two kind of marbles. I am using the marbles as a second resistor in a voltage divider and measuring the voltage drop on it. Theoretically there must be a ...
0
votes
0answers
10 views

Power supply for a fan 12v [duplicate]

I not very good in electronics, I need to feed this fan 12mm, in the specification that requires 12v and 0.250Am. My question is if I can use a DC power supply 12v and 1,5Am i risk of burn it with a ...
-5
votes
2answers
68 views

Ohms to volts i [closed]

Hi I am not sure if I understand this! Ok if I have a power source of 5 volts which then has a resistor of 6ohms and another resistor of 4ohms in parallel with a volt meter would I add the two ...
-5
votes
1answer
57 views

capacitor charging to over specified voltage

Can i charge in real circuit any capacitor, that is rated to 2.7 V to input voltage 12 V as shown in the picture? I mean regular charging and discharging. The current through capacitor will never ...
1
vote
2answers
52 views

Increases in power

I have an electric scooter which I would like to boost or mod for more speed. Currently it runs on a 1600w 48v controller, but what would happen if I changed the controller to a 2000w 48v one, what ...
-1
votes
2answers
64 views

Need to obtain a 1mV signal

I have a 5V power source. For one of my op amps (LM358) I need a 1mV reference voltage as i am comparing it against a sensor input (greater than 1mV). This will allow LM358 to allow my Vcc voltage to ...
3
votes
1answer
170 views

Is it safe? 9v from 12 to 3.3 on ATX PSU

I've an ATX PSU that I've modified to run without a motherboard, to power the many (6 or so) low amperage 12v and 5v devices at my workspace, to reduce # of power adapters plugged in and to provide ...
-1
votes
1answer
52 views

0-5V PWM to analog 0-24VDC voltage with MOSFET

Im having trouble understanding how or if it even is possible to regulate a voltage with a MOSFET. I want to regulate an output voltage of 0-24VDC 0.5A(continuosly) with the duty cycle of a 0-5V 1kHz ...
0
votes
4answers
67 views

Implement ac-dc converter for low frequency and very low voltage without external powering?

Iam using a basic cascade voltage multiplier to boost and rectify the 0.3v ac signal. The circuit rectifies but the boost is very less. So I thought of using LTC3105 after this stage to get a ...
0
votes
2answers
64 views

How is it physically possible that there is no voltage drop across two pins of this DC jack?

I have a DC jack with three terminals. Terminal 1 is tip (+), terminal 3 is sleeve (-), and terminal 2 is a switch, my understanding of which is such that if there is no adapter plugged into the jack, ...
-3
votes
1answer
106 views

Is it reliable to use a 12-bit oscilloscope directly as an ADC? [closed]

I have a circuit for which I need to test a proof of concept in real time. The circuit will output 3 voltages between ±10V, which will be varying constantly, and I need to record and store them. I ...
-3
votes
2answers
76 views

Can a SMPS LED driver glow 6 Watt LED bulb and same Driver is able to glow 0.5 Watt LED?

LED : 150mA * 3.3v =0.5 Watt 6 Watt LED (0.5 Watt* 12) : Which one is best method to arrange LEDs Parallel or Series. At a time only one LED will glow, Either 6 watt LED or 0.5 Watt LED. ...
0
votes
1answer
29 views

Modifying Voltage Controled Amplifier to become attenuator

https://www.fairchildsemi.com/application-notes/AN/AN-6603.pdf Page 3 top left of this also shown in this screenshot: http://i.imgur.com/rp3lYsl.png How would you modify Figure 11 to make a voltage ...
0
votes
3answers
52 views

Voltage divider output with analog voltmeter

I'm using a voltage divider to bring down 24V to 5V and attaching the output to an analog voltmeter gauge. So my question is should I be counting the resistance of the analog gauge into the value's of ...
0
votes
2answers
39 views

Purely Capacitive AC - voltage and current relationship

Studying electronics, capacitors in AC circuits currently. Can not understand two formula's. I see it stated as fact: "In purely capacitive AC circuit Current leads Voltage by 90 degrees." I ...
0
votes
1answer
27 views

Calculating power received and V (rms) given powr loss

The transmission line cable below is 10m long and has a power loss of 1 dB/m at the frequency of the source. What is the power received at the receiver (in dBm), and the voltage (RMS) of the signal at ...
0
votes
2answers
63 views

How to control output voltage on a Buck Converter

I'm fairly new to electronics and I have copied the Buck Converter (LM2678) in the picture attached to convert 24V to 5V. After trying it I have actually converted 24V to 9V and my question is if I ...
-2
votes
1answer
40 views

Adding a variable and DC voltage source LC circuit. How to the Voltage out?

I have the following I want to find out what the Voltage at the Node(\$V_{total}\$). I know that the capacitor and the inductor isolate the two sources from each other. This is what I get after ...
0
votes
1answer
64 views

Loaded Voltage Divider

Could I get some help with this question: Set up an equation for the I (V) containing constants E, R1 and R2 and variable U, when the voltage in M1 is loaded. RL shall not be included in the ...