Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [electrical]

436 questions
27
votes
3 answers

Why solder mask are not applied to RF PCBs

I've gone through some of the RF PCB designs. In which solder masking on the traces are not present. Like this one Is there a specific reason or performance issue to remove that?
Abhishek Parikh
  • 598
  • 8
  • 25
23
votes
10 answers

Are all electrical sockets of my house in the same phase?

Most countries use AC power that is supplied to each house. This AC power is in the form of a sine wave. Suppose I have 2 electrical power sockets in two rooms that are at the opposite ends of my house. Will both the electrical sockets provide the…
Rishi Sharma
  • 487
  • 1
  • 5
  • 15
22
votes
7 answers

Staying in Phase On The Grid

I have been an EE for over forty years and never did find out the right answer to this one.... How do power-stations and transformer switching stations ensure that the power they are feeding into the grid is in-phase with the existing power on the…
Trevor_G
  • 46,364
  • 8
  • 68
  • 151
14
votes
3 answers

Standard Volt and Ampere

A recent question on here asking about how to calculate the accuracy of a circuit got me thinking about calibration in general. In particular, as EEs we routinely use volts and amperes as a unit and yet these are both rather vague and hard things to…
Trevor_G
  • 46,364
  • 8
  • 68
  • 151
13
votes
1 answer

Symbols: Double-arrow circle enclosed "10" on electronic appliances

What does the symbol that says 10 inside the double arrowed circle mean? I have seen a similar symbol on another appliance that had the number 25
user161207
  • 135
  • 2
  • 6
11
votes
2 answers

Is it a good idea to connect a line buffer to ground?

Got a quick question. I'm dealing with 74VHC125BQ,115 and I won't be using one of the line drivers; the rest are connected to UART. So, I'm wondering what I should do with the last one. Is it a good idea to ground its input or should I just leave it…
scriptsNgiggles
  • 197
  • 1
  • 9
10
votes
2 answers

What property of a BJT transistor makes it an amplifier?

I know how we can amplify a given signal using BJT transistors by biasing them. But I would like to know what is that crux property which enables BJT transistor to act like an amplifier. Is it the constant nature of reverse saturation current or is…
GlassAnimals
  • 129
  • 5
10
votes
2 answers

Why does the current not skip resistors R3 and R5 when R6 and R4 have no resistance?

I do not understand why the current still flows through resistors R3 and R5 when R6 and R4's resistance is 0. To me, it would seem that the current would skip R3 and R5, however the answer key says otherwise. I have attached the problem and answer…
David Jones
  • 103
  • 1
  • 5
8
votes
2 answers

Phasing Order in IEC Color Codes

Currently, IEC 60445 international standard is used for conductor terminal color identifications. I've obtained different versions of the standard (2017 being the latest) and also IEC 60446, which was replaced. In the recent versions of all of these…
obareey
  • 115
  • 2
  • 9
8
votes
3 answers

Capacitor Bank Rating

I need to know why capacitor banks are rated in KVAr rather than Farads? Suppose I have one capacitor bank of 10kVAr which is for a rated voltage of 400V. Will this bank provide the same reactive power of 10KVAr at 200V? Ir will it change? If yes,…
Rahul Tungar
  • 89
  • 1
  • 3
7
votes
1 answer

Can't find this electrical symbol

What is the name of this device?
Szymon M.
  • 83
  • 2
  • 4
6
votes
1 answer

Hair dryer fuse too low for spec power?

So I'm tearing down this hair dryer for a school project where I need to make it have variable heat and variable motor speed which can be controlled through an Arduino. I'm currently looking at where I would need to replace the switch and resistor…
S. L.
  • 61
  • 1
6
votes
3 answers

Operating principles of a sawtooth wave generator bootstrap circuit

In one of my assignments, I was asked to explain the working principles of the sawtooth wave generator shown below. The input voltage is a spiked waveform obtained from a differentiator circuit. I realise that the transistor is supposed to act as a…
Tumul Kumar
  • 63
  • 1
  • 5
6
votes
6 answers

Grounding conductor meant to protect electrical devices?

I had a home inspection performed on an old house recently. The inspector noticed that some of the outlets had an unconnected third prong. He told me that the absence of a grounding conductor on the outlet wouldn't cause any harm to the home's…
pr871
  • 1,167
  • 10
  • 23
5
votes
10 answers

Film/TV question: How to build Foam Cutter from only household items

I'm writing a scene for television and I need to make a foam/rope cutter from household items. I've watched several videos, including this one: https://www.youtube.com/watch?v=cM0lP2WCzY0, and determined that I need two sticks (can be anything), two…
Triple9Nickel
  • 75
  • 5
1
2 3
…
29 30