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).

Filter by
Sorted by
Tagged with
0
votes
0answers
23 views

What amperage should a 5 volt power pack be to safely use with a random 5v device to avoid the risk of burning out the device (i.e. an apple tablet) [duplicate]

I have a number of variable power packs one of which supplies the 5volts I need to for a particular device. The output is "500mA MAX". I worry that as happened once before with an ipad I ...
0
votes
1answer
39 views

Do Output Voltage rails get an identifying symbol in schematics?

For example, I have a 3.3V regulator using 5V input from a USB port. I use that output 3.3V rail all over my schematic. Sure, I can read the entire schematic and see - yep, that's the output. But is ...
0
votes
1answer
31 views

What does it mean to have a large time constant of a RC network than the time period of an input AC signal

What does it mean to have a large time constant of a RC network than the time period of an input AC signal? Can someone tell me how to understand this and what sense does it make?
2
votes
3answers
275 views

Equation (mathematical function) of ramp signal vs saw tooth signal

I have a sawtooth current source whose peak value is 1A. 0A to 1A. with a frequency of 1kHz. This current source is going to charge a 1F capacitor, so I was trying to find the equation for the current ...
-2
votes
1answer
59 views

DC DC converter

I am newbie trying to build a circuit, please help me out. I am trying to build a DC-DC converter whose input will be 24V and output would be 5V 3A. I have picked AP63301WU-7 DC DC converter from ...
0
votes
2answers
57 views

Any examples of layout where analog ground and digital ground are connected together

I have read about layout where analog circuit ground is separated from digital ground. Though, I have not seen any examples and unable to find on google, can someone help me with some pictures on how ...
1
vote
2answers
89 views

Low voltage at N-Channel source pin

I made a pcb which uses an N-Channel Mosfet for enabling/disabling the NTC thermistor as in the schematic below. The problem is I get 2V at the Drain pin instead of 3.3V. I measure 3.3V at NTC_TRIG ...
0
votes
2answers
71 views

Voltage drops when current reaches limit on supply

Why is it, when I'm powering a circuit via a lab bench power supply set to limit 2 mA and the current drawn from the circuit reaches the limit, the supply voltage drops?
0
votes
3answers
38 views

How do I determine the input voltage for a solid state relay?

5v + 1k ohm resistor input to PVG612PBF (SSRelay) Datasheet Is this the correct voltage/resistor to suit this relay? If not, how would the voltage or resistor be selected for this specific SSR? How do ...
0
votes
0answers
40 views

Find Vout with voltage divider + pull-down resistor

I have to calculate Vin (~5 V). After using the voltage divider formula the Vout value is pretty close to the value measured by a multimeter, but a little bit low. The question is, what is the formula ...
0
votes
3answers
109 views

80% amperage rule for continuous loads?

I'm trying to understand how an electrical load affects a circuit. Let's say, for example, I have a setup that is on a 120 V, 15 A circuit: 120 V x 15 A = 1,800 W max if we have a continuous load (3+ ...
-2
votes
0answers
40 views

How to tell whether a battery needs replacement? [closed]

I have this m365 scooter for about 3 years now but riding it feels really weak, especially when going uphills. It is recommended to change the battery after 500 charges, that is - now. But the ...
2
votes
3answers
193 views

Can I use logic inputs higher than Vcc but still in the operating voltage range of the IC?

I'm trying to create a battery-backed-up non-volatile RAM using an SRAM IC (AS6C1008 from Alliance Memory, datasheet). My idea for separating the backup battery from the main voltage source is to use ...
-1
votes
2answers
57 views

Do I require an amplifier?

I am planning to do a simple DIY project to replace the cable on my Sennheiser HD 598, which has 50Ω impedance, with a bluetooth receiver, a 3.7V 1000mAh battery (and a charging board). My calculation ...
0
votes
1answer
80 views

Can I send 12 volts to a 6 volt relay?

I currently have a 12 volt LED light strip that I would like to work with my welcome lights on my vehicle. The system outputs 4.5 volts for the welcome lights, then it goes up to 12 volts once the ...
8
votes
3answers
256 views

How to choose capacitor voltage rating for ESD protection?

I understand the basic calculations on capacitors for ESD protection. In a nutshell the higher the capacitance the lower the final voltage will be because the charge of the ESD event will be "...
0
votes
0answers
68 views

When running a bigger wire to deal with voltage drop on a 240V circuit, do I now need to run a neutral as well? [migrated]

I am running wire for a 240 V, 20 A split-system AC over a hundred feet and the voltage drops below the allowed NEC 5% voltage drop. So I have to step down the a wire a gauge and run a #10 wire which ...
1
vote
1answer
62 views

How to measure the stability of sine wave peak-to-peak voltage

I am currently using AD9833 to output a sine wave signal. I have seen the sine wave signal on oscilloscope and saved a CSV file on my flash drive. I plan on using an Excel or Matlab to determine the ...
-3
votes
0answers
33 views

bias voltages dc analysis

It might seem a silly question but given this circuit : I'm quite confused which terminal is biased, here is what I think : Source of Q4 and Q3 is at +1v 2.Source of Q6 is grounded 3.Drain of Q5 is ...
-1
votes
1answer
36 views

VCO tuning voltage range starting from higher than 0 V

I have seen some VCO datasheets. In every datasheet, I see that the tuning voltage range starts from some value above 0 V (like 0.5 V, 1 V etc). So, what would be the frequency at 0 V? And why do they ...
-1
votes
3answers
55 views

CMOS active crystal oscillator output voltage uncertainty

I want to use SG7050CAN CMOS active crystal oscillator as reference input to ADF4106 PLL. The input voltage level is 0.8/AVDD Vp-p min/max. Now, the SG7050CAN datasheet says, it's low voltage is 0.4 V ...
0
votes
0answers
87 views

Creating a 500,000-1,000kV dc power supply [closed]

For an experiment I need to create a really high voltage, so is there any way I can create a 500 - 1000 kV dc power supply? I found some transformers but they only make ac current. Currently, I'm ...
1
vote
1answer
99 views

Can a 12 V LED dimmer be used with a 6 V incandescent load? [closed]

Can a 12 V LED dimmer be used with a 6 V incandescent load? I'd be interested in knowing what factors make such an arrangement suitable or unsuitable. Specific example: I bought a 12 V, 60 W Dimmer ...
0
votes
2answers
90 views

Correcting MOSFET gate voltage

I'm working on a project where a IRL520N controls some LEDs but I ran into a problem. In order to activate the MOSFET I'm using a microcontroller with an output of 5 V, but the datasheet says that the ...
-6
votes
0answers
25 views
-1
votes
2answers
68 views

Buck/boost converter (XL6019) produces wrong output voltage when powerbank goes less than 5v

I recently bought a buck/boost converter (XL6019), and I was trying to boost to 9 V to power a device (RC Car). My idea was to use a power bank instead of 6 x 1.5 V AA batteries, but I realized that ...
0
votes
1answer
42 views

Electric field in a circuit and potential drop

With reference to the above image: Here the battery produces a constant (will it be constant? pl. explain) electric field across the length of the wire, lets say its value is \$\vec E\$ . This field ...
1
vote
2answers
71 views

Calculate the integral of a saw tooth wave

My question is with reference to this question over here Suppose, I have a saw tooth current source with peak value from 0A to 1A with a frequency of 1kHz and I need to calculate the charge of the ...
1
vote
1answer
44 views

Effect of Internal ADC capacitor in Microcontroller

The input pin mentioned in the below image is the input pin of the microcontroller. It explains that the internal capacitor of A/D peripheral of MCU should be very much less than the external ...
0
votes
1answer
97 views

Voltage issue on pull-up resistor

I have an I2C sensor circuit, 3.3V applied to SDA and SCL pin through 10k resistor. I2C communication is not working so I have measured the voltage drop across the 10k resistors. It drops 2.86V and ...
4
votes
1answer
24 views

Does partial distance occurs in distribution transformer?

I've seen that in some substations online transformer inspection is performed through partial discharge detection sensors. As partial discharge depends on voltage so I was wondering if these kind of ...
0
votes
6answers
138 views

Average value and RMS value

I am trying to understand the concept of RMS value. From whatever I have read and the tutorials I have seen, I have seen them derive the RMS value only considering the first positive half cycle of the ...
0
votes
1answer
30 views

LT3546 voltage unstable at low current

I am using this IC in my design as 3.3V power supply. My design basically has 2 variation. So design1, has a few more circuits powered by the 3.3V. and design2 has less circuits. Following the ...
3
votes
0answers
81 views

Voltage level detection circuit

I am trying to build a voltage detection circuit, that would check if the input voltage is high enough. The circuit is based on TL431 as a comparator. I would like to have two threshold voltage with ...
0
votes
0answers
52 views

What is flashover in PCB and the physics behind it

I was learning about PCB trace to trace spacing. For high voltage traces if the spacing is not proper, what I read is flashover will occur. I searched on google about what is flashover and how it is ...
14
votes
4answers
2k views

What is the difference between a linear regulator and an LDO

Can someone tell me what the difference between linear regulators and LDOs is? From what I have read and understood, it is that linear regulators and LDOs don't use switching elements, but I think ...
0
votes
2answers
41 views

What is the formula or any method to calculate the value of the output capacitor and inductor in a buck converter

I have using a buck converter whose output is 5V and 1A. Can someone tell me whether these is any formula to calculate the value of the output capacitor? Like, without involving the switching ...
1
vote
1answer
93 views

Why is EMF = I(R+r)?

A voltmeter is connected to a dry cell battery. The voltmeter reads 9 V. A 24Ω resistor is connected across the terminals of the battery and the voltmeter reading becomes 7.2 V. Calculate the internal ...
0
votes
3answers
111 views

Why is there EMF present when there is no current?

Current means the rate of flow of charge. Electrons are the ones that carry charge in current. From the definition of EMF (electromotive force), When no current is drawn from cell, the potential ...
0
votes
1answer
87 views

US Sewing Machine 120v 60Hz in the UK [closed]

I need some advice. Bought this sewing machine from Amazon US and I have it here in the UK. I am not worry about getting the step down voltage but how can I get the frequency up to 60Hz? Some ...
0
votes
1answer
40 views

Supply voltage range for the OP07 op-amp

OP07 op-amp datasheet When it says "Supply Voltage Range +-18V," can I supply it 0 to 36V if I want only single ended operation, or am I limited to 0 to 18V only? Whatever is your answer, is ...
1
vote
2answers
76 views

Relays connected in series?

I have 2 identical relays (same specifications) whose working input voltage is 12V DC. Can I connect the 2 relays in series by supplying 24V DC so that there will be 12V DC drop across each of the 2 ...
1
vote
1answer
37 views

Can I control a solenoid valve below its nominal voltage?

I need to control the following 2 ways direct solenoid valve ("Series 252 D01") : https://www.emerson.com/documents/automation/catalog-series-252-dental-manifolds-asco-en-6779448.pdf It is ...
0
votes
1answer
43 views

How to safely calibrate a step-up DC-DC converter?

I have a simple DC-DC step-up converter. For example this one. It has a potentiometer and I need to rotate it using a screwdriver to change voltage. How do I safely adjust output voltage without ...
3
votes
1answer
102 views

Is a battery pack connected parallelly or in series?

I have a circuit of a battery pack of 4 18650 and a 4S BMS. See the picture below. The question is: is my understanding correct that this circuit means that the batteries are connected in a series, so ...
-3
votes
1answer
112 views

13.8V dc for a 12V dc device [duplicate]

My device comes with a wallwart rated at 12V dc/1.5A and the manufacturer specifically warns not to use over 12V dc. Is it safe to use a switching power supply rated at 13.8V dc/30A?
0
votes
1answer
57 views

LTspice simulation: unexpected behaviour of circuit

I am trying to build a JFET driven current source in a more complex circuit topology than shown here. Unfortunately, the simulation is not giving me the results I would expect. I could trace the "...
1
vote
2answers
293 views

Unexpected behavior when using 5V from one power supply and Ground from another one

I am trying to use an old phone charger with 5V DC output. I measured the output to be 6.4V. It works for powering an ESP8266 through VIN but does not work to power an IR receiver I want to use. The ...
0
votes
1answer
49 views

How to increase the fan speed connected to a usb port

I have 6 PC fans 12V 0.12A connected in parallel. They are connected with a usb cable to a mobile charger. When I was connecting them to the motherboard they were much faster than now though the ...
2
votes
5answers
469 views

What are the fundamentals behind this p-channel MOSFET / driver circuit?

I have this schematic below. I have a circuit to switch 8 V power using a MOSFET and an NPN transistor with an Arduino's 3.3 V. The power of the switched side will be around 2 A (if this matters ...

1
2 3 4 5
136