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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34 views

Electron velocity in a conductor

I have a question : The electron beam in TV picture carries $10^{15}$ electrons per second, determine the voltage needed to accelerate the voltage needed to accelerate the electron beam to 4W I need ...
53 views

Frozen Sim Card Holder Failure

I’m currently having an issue with a SIM card that can’t be read by an LTE chip. It was deployed in a product outdoors where the temperature dropped to around -20C and the connection suddenly dropped ...
56 views

Why does the resistance of a brushed Dc motor from an experiment kit vary?

I am currently performing an experiment in which I measure the Current and Voltage of a motor that experiences changes in load. I am using a 3V (3V battery) supply however the voltmeter's (connected ...
44 views

LED Driver Pin function

I have this LED Driver - A80604 I need to generate 30V for my LED Driver String for generating 300mA. In a previous question, I received an answer that I need to fix the current using the LED Driver ...
58 views

Can someone help to find me a horizontal (90degree) connector? [closed]

I am having this connector - FH40-30S-0.5SV. This is a vertical connector and I am requiring a connector with similar pitch and pin count but instead of vertical (straight), I want horizontal (90 ...
59 views

Electromagnets and voltage

I'm thinking of getting two electromagnets. On Amazon, it reads 24V 400N. What does that mean? Of course, it would be DC since that is what electromagnets are based on. I will use a simple series ...
78 views

Meaning of “Supply Voltage: 3~132V” on an electric drive system plate? [closed]

I have an electric drive system for a garage door that has the supply voltage mentioned above. What does the 3~132V mean?. The output torque is 190 NM and the output speed is 85 rpm. The input current ...
30 views

How to calculate the voltage at the OUT point in this PWM creator

This is a Circuit for creating a PWM signal,I have the results but I wanted to know how I come to this results,because I dont really know!Thank you!Here DC=50%,what about DC=75%.Please help!!
22 views

USB-C and Apple Lightning inputs

I am wondering if there is a way for a device to receive power from both USB-C and lighting connectors. They would obviously be connected individually. I was also wondering if it is possible to wire ...
48 views

Controlling 60v with mosfet through pwm

I got this setup for controlling high voltage with PWM through a Mosfet ranging from 0-60v. Im using the PCA9685 for generating the PWM signals and then the mosfet FQP30N06L for controlling the ...
49 views

SparkFun Power Driver Shield Kit for controlling 60 V input [closed]

I just bought SparkFun Power Driver Shield Kit. I read in the specifications that it was possible to control up to 60 V using PWM. I have got a project where I need to control 60 V with the PWM so I ...
92 views

How to fix my simple MOSFET power switching circuit?

In my design the goal is to create a simple switch between power sources using a MOSFET. J2 is just a connector for the main power source which remains connected VDD is connected to a USB port VREG ...
318 views

Assigning a notion of voltage even when there is a changing magnetic field

In Walter Lewin's lecture, he finds depending on how you keep the lead of the voltmeter for a circuit in a changing magnetic field, you will measure different values]. This experiment is discussed ...
97 views

Not getting the expected output from my switching regulator

I am working on a project using a TPS54202H switching regulator. The power supply is currently in 12V DC @ 60mA and am expecting a 5V output. I followed the datasheet schematic but when I power it up ...
112 views

How to modify the supply voltage requirement in a circuit?

I am a beginner in Electronics; I am learning the basics and am trying to take up circuitry as a hobby! My query is regarding power supply requirement for any circuit. Take, for example, a circuit to ...
106 views

Why is Arduino Uno Rev3 input voltage specified up to 20V? OpAmp

The Arduino Uno Rev3 has an OpAmp (TI LMV358IDGKR datasheet) where the non-inverting input ("CMP") is connected via a voltage divider to Vin. The OpAmp's supply is connected to 5V. On the ...
1k views

Why must the voltage drop over resistors in parallel be the same?

I am wondering why it is the case the when resistors are connected in parallel the voltage drop over them must be the same? The reason I have seen arguing for this is that the electrons before the ...
526 views

What would a voltmeter measure if you had an electromotive force generated by a changing magnetic field?

Suppose I had a circuit of this sort, and there was a changing magnetic field through the central triangle: Faraday's law suggests there will be a voltage through the loop. The voltmeter is supposed ...
38 views

Time varying voltages [closed]

Hi I am in an introductory circuit analysis course and we just got to the portion over time varying voltages and currents through inductors and capacitors. We aren’t on the alternating current section ...
27 views

Differential Signal Measurement best practice

I have 4 differential signal pairs (LVDS Data lines and Clock) running between my Microcontroller and TFT. There are no test points over the lines. Can someone tell me what is the best practice and ...
124 views

Controlling two devices with the same push button

Currently, I have a push button (SW) controlling a device (DEV1). What I would like is to another device with the same push button (SW). I measured the voltage on DEV1's and DEV2's push button inputs, ...
72 views

Estimating power from a voltage waveform

I'm working on a project in which I'm using a photodetector module. I'm transmitting a sine wave. From the output of the photodetector (C12702-12) I can visualize the transmitted sine wave on the ...
45 views

Help in identifying the motor

I am total noob in electronics field. I had some broken electonics appliances lying around house so now I am trying to build something out of it. Can you guys please help me with identifying the motor ...
33 views

Terminal vs induced voltage for a transformer with respect to the voltage rating

Suppose we have a 2200/220 V non-ideal transformer. Based on the image below of a non-ideal transformer, would 2200V be the primary terminal voltage (V1) or the primary induced voltage (E1)? Similarly,...
27 views

Multiple buck convertors on one plug/power source

I have a question in regards to using multiple buck convertors. I want to use a 12v plug/supply to run one wire to the 12v, two 5volts and one 8volt. What I want to know if it’s possible to have a ...
32 views

Fast voltage regulator for output of an function generator

First, I am not an expert in the electrical field:) In a real-time control system (in LabVIEW), for actuating a piezoelectric, I use the generated signal (sine signal 20khz and 10<V<100 Vpp) ...
32 views

What would be the correct amount of voltage to power an Arduino UNO, XBEE shield (with XBEE module), and five Tower Pro SG90 Servo motors?

I am designing a glove-controlled robotic hand using Arduino UNO and XBEE. For the hand itself I am using the adafruit 16 channel PWM Servo Shield and using 5 SG90 servos for each finger. My problem ...
71 views

Why does a change in excitation of an alternator affect only kVA and not kW?

http://www.brainkart.com/article/Effect-of-Change-of-Excitation_12208/ The explanation is there but I feel too dumb to be able to understand it and connect it to the visual. Can someone explain it in ...
47 views

5-20V VBUS sensing with 5V only IC

I am designing a board with a FT230 USB to UART IC. In battery powered applications, one of its GPIO can serve as a VBUS sensing pin. However, the FT230X was designed for 5V applications, before the ...
29 views

Addition of AC Voltage Polar Form

Question 5 Part A Only. I tried converting polar form to rectangular form to add the AC voltage sources and converting it back to polar form. I got the angle (10.09 degree) right but not the r-value ...
50 views

Pi Zero / GPIO Pins / +12V Power and Sharing Ground

I need a sanity check on my schematics before I pay for JLCPCB to make my PCB board. Goal: To have my Pi Zero fire a pyro charge in a model rocket. Setup: GPIO-20 Sends a signal to the MOSFET Gate, ...
68 views

Is the peak-to-peak voltage the same as the peak voltage in rectified voltage?

I have a homework in which in need to calculate the peak-to-peak voltage through a half-wave rectifier, center tapped full wave rectifier, and bridge full wave rectifier. What is confusing is that ...
20 views

When changing rotor current in alternators, the pf and inductive part of the current changes but the resistive part does not. Why is this so?

Given a current for an alternator $I = I_R - jI_X$ When the rotor current changes, the excitation changes so the magnitude of the generated voltage changes. The current changes, but only the ...
31 views

Question regarding Connector

Can someone please help me to understand what type of connector is the below : How do we classify this 99S12D-40MA5-y connector which is on page 33 in the Catalog document? Do we call it as a ...
55 views

Use of series inductor to control small 120v blower

I want to run the 120vac blower less agressively. Like 9ov instead. I find that I can series install an inductor and that works well. Q1 Would it be best to use a buck xfmr instead? Q2 How does ...
72 views

Can we charge a battery rated at 42V 1A using 12V 1A charger?

So assuming that the battery is fully dead, is it possible to charge abattery rated at 42V 1A using 12V 1A charger. I have seen similar questions that are almost using same volts or slightly higher, ...
51 views

How do I get an output of 24V from a K30319 adapter? [closed]

The K30319 adapter is a 24V adapter made by Canon in Vietnam. I pulled it out of a Canon printer someone chucked in the garbage. The adapter works as far as I can tell. I'd like to use this adapter to ...
99 views

Arduino power input [closed]

Arduino power input, what pin can you use for 12V DC to supply my Arduino? What's voltage limit can the Arduino can handle?
81 views

How to convert sine to exponential form? [closed]

In this question, he converted the sinusoidal voltage to exponential voltage. what's the formula used here ? This is not the same one used in this video Here is the formula derived in the video
153 views

Why does this Zener diode circuit not produce the Zener voltage?

Why does the measured voltage at the op-amp input equal 2.02V? simulate this circuit – Schematic created using CircuitLab
50 views

Can I measure analog voltages for a circuit with multiple power supplies?

I have two components in a circuit: An Arduino Uno R3 and a Wind Sensor Rev. P. See diagram below. The wind sensor requires 12V to operate, so I powered it with an external power supply (provides 12V ...
80 views

How do VAC ratings of flyback transformers translate to VDC ratings of flyback converters?

I am trying to design a 40-50W flyback converter but I am struggling to select an appropriately rated transformer. While most flyback transformers are rated in AC volts, plenty of flyback converters ...
99 views

Voltage stabilization

I have several motors, and a microcontroller. The microcontroller sends 3.5v signals to the motors, which are powered by a separate 5v source. (The microcontroller also runs off the 5v.) Problem is,...
86 views

How do I convert 5 V to 9 V?

I am building a guitar pedal, and I would like it to run of a 5 V rechargeable battery instead of a 9 V battery. Does anyone know how I can accomplish this? Thanks for reading!
89 views

What's the correct approach to this RLC circuit problem about RMS voltage?

How are you supposed to determine $V_{C,RMS}$ without R, L or C? I drew a phasor diagram and used $Z=\sqrt{R^2+(X_L-X_C)^2}$ but am unsure on how to proceed from here as I do not have values of R,...
54 views

Small voltage reduction

I have a home built radio which can take a voltage range of 2.2V to 3.6V. I wish to use a Lion battery that is 3.87 volts when fully charged. Can I sensibly reduce the voltage to 3.6 simply? I have ...
190 views

Turn on voltage by using smaller voltage

I'm wondering if there's a way to create a current controlled voltage source. At the moment I have a mosfet (NPN, PN2222) connected in series with a positive 5V terminal and ground. I control that ...
46 views

How to choose diode?

I built a scaled down model of my idea. Since current flow was always under 1A, I used a 1N4007 diode to keep the current unidirectional in the circuit. Now I am planning to build a full size model ...