Questions tagged [ac]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0 votes
1 answer
43 views

Basic questions about power grid stability with variable loads and sources

I am curious about integration of renewable energy in electricity grids. I am a mechanical engineer and understand energy and power but I have little knowledge about electricity. I will be thankful if ...
user avatar
  • 148
1 vote
0 answers
38 views

Household 3 phase devices

So, I'm not sure if this is the right place to ask this, but have been working on modifying a lawn mower robot that has, for roughly 3 years now been stored under less than favorable conditions. As a ...
user avatar
  • 265
0 votes
3 answers
49 views

AC/DC Laptop adapter power losses

I have a laptop power adapter shown in the picture below. It is written there 170Watt INPUT: 100-240V ~ 2.5A OUTPUT: 20V 8.5A I believe for AC Input they mean Root mean square voltage/current. for ...
user avatar
  • 113
0 votes
1 answer
74 views

Are AC generators more efficient than DC generators?

I've been doing some research into AC and DC generators, and I was wondering if AC has any advantages in terms of efficiency. Given that AC generators are usually brushless while DC generators ...
user avatar
  • 11
3 votes
1 answer
252 views

Arduino DAC to Speaker

I'm working with an Arduino Due's two DAC pins. I want to output to a single 4W 5.7Ohm speaker to test my code, with the intent of eventually outputting to a set of speakers (woofer, mid-range, and ...
user avatar
1 vote
1 answer
36 views

Design of a hydrogen and corrosion sensor query

I’m designing a hydrogen and corrosion sensor. A thin film changes resistance based on hydrogen concentration. Then the capacitance between two electrodes will change depending on substrate thickness (...
user avatar
3 votes
0 answers
41 views

Understanding transformer secondary winding

I purchased a step down transformer from a junk yard. I tested the transformer and it works but I am confused as to the secondary winding. The primary side has these markings G 0V 100V The secondary ...
user avatar
  • 43
0 votes
0 answers
38 views

Issues with Building AC Generator

So we are trying to build an AC generator, an alternator, if you will. We are using a 5" PVC pipe for the body with a hole drilled diametrically, through which a bolt passes. Inside of this pipe, on ...
user avatar
2 votes
1 answer
94 views

Calculate amount of evaporative coolers needed to cool down an area

I have a task to create a software that calculates how much evaporative coolers are needed to maintain a certain temperature in a given room. I need to create a simple form, where variables are next : ...
user avatar
2 votes
0 answers
40 views

Breakdown voltage of electronic devices

Diode and transistor have reverse breakdown voltage. Are these devices permanently destroyed under such voltage? Also, do these devices have breakdown voltage when AC voltage is applied? How much AC ...
user avatar
  • 21
-2 votes
1 answer
58 views

Which Generator is "Better": DC or AC? [closed]

So, I have a project where I have a bicycle that powers a type of generator. I have everything else done, but I need to pick a generator. My first problem is that I don't really know which type of ...
user avatar
2 votes
1 answer
48 views

Are there any variable frequency drives that work digitally?

By this I mean can any DC to AC variable frequency drives invert digitally (no moving parts) and if so how do these work? Is this possible for both sine and square wave inverters?
user avatar
  • 240
2 votes
0 answers
191 views

What is the maximum frequency of an AC current?

I saw that the rpm of a synchronous motor is proportional to the frequency of current alteration and I was wondering if there is a theoretical maximum frequency (regardless of magnet strength)? Also ...
user avatar
  • 240
0 votes
3 answers
66 views

Increasing speed and efficiency of ac induction motor

If you wanted highest efficientcy and speed from an AC motor what would you do? Could the rate of alternation of current be optimizes? More windings? Materials? More lamination? Other factors I haven'...
user avatar
  • 240
2 votes
1 answer
368 views

Mechanically increasing RPM of ac induction motor

If you spin the stator of an AC induction motor than would the rotation of the rotor increase? Or would it have a different affect such as moving with a higher force?
user avatar
  • 240
0 votes
1 answer
59 views

AC induction motor

Could the rotor be shaped like a fan inside the stator of an AC induction motor. And could the stator act as a duct. Would this lead to a high airflow:materials used. Thanks
user avatar
  • 240
7 votes
1 answer
1k views

Is a 3 Hz beat frequency from my neighbor's HVAC a sign of a malfunction?

I'm being annoyed by a pulsating hum which comes from my neighbor's HVAC system. I read up a little on the design of HVAC systems and I came to a tentative conclusion that what I'm hearing is a ...
user avatar
-3 votes
1 answer
1k views

How to convert VDC to VAC at a high frequency? [closed]

How to convert 10 VDC to VAC at a high frequency, say 10 MHz? VACpp can be +-10V or +-5V.
user avatar
  • 1
1 vote
1 answer
77 views

Will AC Motor Maintain Speed of Descending Object

Suppose we have an AC motor which needs to lower an object at a set speed. We use a PID loop to determine and correct positional errors. Presumably the PID loop will keep the current low as most of ...
user avatar
  • 137
2 votes
3 answers
3k views

How does single-phase AC synchronous motor work?

In a recent question of mine about microwave plates, jpa correctly identified the type of motor used for microwave plates as a specific variant of AC synchronous motor, equipped with gears that reduce ...
user avatar
  • 6,123
10 votes
4 answers
19k views

Does a transformer use power when output isn't under load?

I was reading about how AC to DC converters work with a step-down transformer and then a diode bridge to convert the lower, stepped down AC voltage into DC. What I don't understand is since the input ...
user avatar
  • 5,930