In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of switch is an electromechanical device consisting of one or more sets of movable electrical contacts connected to external circuits. When a pair of contacts is touching current can pass between them, while when the contacts are separated no current can flow.
Switches are made in many different configurations; they may have multiple sets of contacts controlled by the same knob or actuator, and the contacts may operate simultaneously, sequentially, or alternately. A switch may be operated manually, for example, a light switch or a keyboard button, or may function as a sensing element to sense the position of a machine part, liquid level, pressure, or temperature, such as a thermostat. Many specialized forms exist, such as the toggle switch, rotary switch, mercury switch, push-button switch, reversing switch, relay, and circuit breaker. A common use is control of lighting, where multiple switches may be wired into one circuit to allow convenient control of light fixtures. Switches in high-powered circuits must have special construction to prevent destructive arcing when they are opened.
Homework Statement
The following figure shows a circuit containing a bulb, switch and battery. Four voltmeters are connected in it to measure potential difference. Which voltmeters give non-zero readings and which ones read terminal potential difference when the switch is 1) open and 2) closed...
Homework Statement
Homework Equations
Vf+(Vi-Vf)e-t/RC
Tau = RC
The Attempt at a Solution
[/B]
Normally, I would use the eq'n mentioned above to find Vr in an RC circuit. However, this second capacitor is throwing me off. Is there a new equation I should use? How do I think about this...
Hi, currently I am a freshman who is majoring in Biosystems Engineering. I selected this major because I did a lot of research into biology undergrads and I didn't like what I saw. I got the notion that these majors did not emphasize the technical skills necessary to do well in a science...
Homework Statement
Seven equal resistors, each of resistance 2Ω are connected with a battery of 3V in a circuit shown. If i1 is the current when the switch S is open and i2 is the current when switch S is closed, find the value of i1/i2.
Homework Equations
1)Equivalent resistance formula...
Homework Statement
a) If this mixer is connected to a matching 50Ω resistor, what is the conversion gain?
b) IIP3 (Third Order Intercept Point) is 15 dBm, what would be A1dB?
c) What is P1dB?Homework Equations
https://www.ece.ucsb.edu/Faculty/rodwell/Classes/ece218b/notes/Mixer1.pdf#page=9
b)...
Homework Statement
We have a circuit with a battery, two resistors, a switch and a capacitor. We assume that the battery has a switch so that we can choose whether it should be a voltage source for the circuit.
a) At time t = 0, we put on a voltage Vs
over the battery in the circuit. What is...
I need a better understanding of limit swtiches and servo motors than I'm getting from Wikipedia :)
Any website/textbook recommendations? (My background is physics.)
TIA!
For a project, I need a means of switching a high-current circuit between two inductors. The purpose is, each inductor serves as an electromagnet, and they are switched every 15s or so in order for one of the two to cool before starting again. The system I've designed uses arduino as a...
This is a diagram of an old 1970's directional flasher switch. Can anyone walk me thru the details of its operation?
https://drive.google.com/open?id=1OI6bL3PXfDx8lmg2eiWDCVHg9rgm0gYl
Thanks.
Hello, I'm having trouble thinking of ways that I can measure the temperature of an object that I am heating using an Induction Heater. A little background: The coil and workpiece will be submerged in liquid, and due to most thermometers being metal it won't work with the induction heater. I'm...
Homework Statement
Describe the principle of operation of reed switch and LDR using wheatstone bridge and potential divider arrangement
I can't find any website that says a reed switch uses a wheatstone bridge or potential divider arrangement. The only find I have found it that that a magnet...
Homework Statement
The switch in the circuit in has been closed for a long time. At the switch is opened. a) Find i0 for t>=0 (b) find v0 for t>=0
I don't understand the effect of the switch in the position it is in. It's acting as a short circuit, I think, so presumably the capacitor doesn't...
Hello,
I was wondering if I could get some help understanding the wiring of a knob switch (Link 1 and 2). It's on an old machine that we got and I can't find any schematic for switch. The purpose of the switch on the machine is to raise or lower a steel arm. There are actually two boxes...
Homework Statement
Homework Equations
V = I R
Q= CV
The Attempt at a Solution
When the switch is connected to position a :
20-106 * I = 0 ( KVL)
Vc = 0 , because the switch is connected for a long time.
I = 2*10-5 A
When the switch is connected to position b :
Q/(4*10-6) - 106 *2*10-5 = 0...
Hello, I'm new to electronics and I'm reading a book currently to learn more about the topic. I'm currently on a section where I'm building circuits where I'm using a transistor as a switch. I decided to experiment with the circuit they gave me and put it in a simulation software called Proteus...
Hi.
I am working in on a Ring Main Unit of Siemens make. Today, my senior asked me the same question. As per my understanding, a circuit breaker is make or break switch. I mean, when fault occurs the circuit breaker trips, protecting the equipment connected to the line.
I have no information...
Hello,
I'm currently constructing an electric bicycle using a 500w 24v motor, 2X24v 7ah batteries (maybe 4 later on). I bought a 24v 30a dimmer switch to use as a "throttle". During the intitial test (on a table, not on the bike!) It worked absolutely fine for 2 minutes, but then began to smoke...
I would like to know if there are any general equations (such as the AC transformer equations) that describe a switch mode DC transformer. By this i mean a constant frequency DC signal (50% duty cycle) that ranges from 0V to some max voltage on the primary coil and outputs some higher voltage on...
Homework Statement
Consider the circuit
How long after the switch is closed does the voltage across the resistor drop to Vf = 20V. Answer in units of s.
Homework Equations
Tc = RC
Q=Qm(1-e-t/RC)
The Attempt at a Solution
[/B]
RC = .0003026
11 = 31(1-e-t/RC)
.3548 = 1-e-t/RC
1.3548 =...
Last December I applied for physics PhD positions in the US. In my personal statements, I mentioned my research interests as well as specific faculty I'd like to work with. What happens if I receive an offer of admission from a school but decide that I'd prefer to do research in a different...
Hello,
After finishing my PhD in EE/wireless communication from Canada, I could secure postdoc positions in the academia. But wanted to make a transition to the industry because it pays more and it is more stable. Applied to telephone companies for R&D positions, with no luck. I tried more...
Homework Statement
Hello Everyone, a pleasant good morning to all :)
I will attach an image that shows a diagram of a circuit.
The question based on this picture is as follows:
''When switch S is closed, the Lamp L, lights. Explain how this occurs.''
Homework EquationsThe Attempt at a Solution...
So you I've screwed up in Mechanical engineering courses due to a combination of personal reasons and some tough professors. I have discovered that it is possible to finish a BA in mathematics in the same time frame as the Mechanical engineering BS degree, only one semester + the summer. I've...
Hey!
I’m kinda down in the dumps right now because of school. I’m in my first year of physics and uh I’ve had a couple bad tests for some of my courses and I’m starting to worry that if I can’t even do really well right now, how will I make it through my upper years. I really don’t want to...
I don't know if it's the same for a car but bikes uses a starter relay to set off a starter motor which cranks the engine.
Bikes have a side stand for you to lean the bike against when stationary. In case the rider tries to start the bike with side stand deployed (could cause crash if forget to...
So in high current circuits which involve say a starter motor in a car we need a starter relay since a normal switch cannot handle the high current flow.
I think the reason I'm asking this question is because I don't understand what exactly makes the relay be able to handle the current unlike...
Homework Statement
What is the heat generated on closing the switch?
Homework EquationsThe Attempt at a Solution
[/B]
On closing the switch, the potential difference across each capacitor should change which would cause it to charge and hence cause heat loss through the capacitors.
But...
Hi. I'm searching for a name of the spring mechanism that snaps-up and snaps-down this type of Switch cover https://cdn.sparkfun.com//assets/parts/6/9/9/0/11310-03a.jpg .
on the left side of this red cover, you can clearly see the spring and few other things, that makes it to resist any change...
Hello! I am writing this to get some ideas for what to do with my future. This will be a long post so I should start by introducing myself…
I am currently in the last year of my PhD studies and I will be starting my thesis soon (at least I hope so). My work is on classification theorems in...
Homework Statement
before that, can you tell me about "current flow in this circuit" if :
A. the switch is open
B. the switch is closed
the Question is
No. 1 Calculate the resistance of R if the value of the current I in the figure is 0.50 A. ( i think it is related to no 2)
no 2. Calculate...
Hello People!
So currently I have an AC input going into a capacitor and inductor in parallel, and I want the output from the capacitor and inductor to go into a switch that flips from outputting the capacitive load's output and the inductor's load output, a little diagram is shown below...
So I've decided to switch my major from engineering to physics. I finally got courage to man up and do what I want and I'm super excited. However, I currently do research in the BME department with a professor who is the top in his field. The research is more biophysics/applied physics type...
Homework Statement
Homework Equations
None
The Attempt at a Solution
The answer is B, bulb B will be brighter than before.
My thought was that initially, the current gets split so that 2/3 I0 goes to the branch with 2 bulbs, since it has twice the resistance of the first branch, and that...
Hi,
I want to be able to vary the amount of capacitance in a circuit, ideally I'd like to be able to turn a knob to tap a bank of capacitors, something like the attached picture.Is there some sort of switching or device available that anyone can think of which does this?
Cheers
Hi Guys,
Im totally new here and I'm not even sure if this is the right forum, but I think there are a lot of people here who know all about electronics.
Ok so I bought an electric scooter. It has an on/off switch but no kind of security. So if I hook it up to a pole and leave, people can still...
The "should I switch from Physics to Engineering?" question has been beaten to death - so I’m sorry for repeating a variation of it. But, I haven't found answers regarding my specific case.
I just got accepted as a transfer student to UCSB for Physics, which I’m pretty happy about.. because I...
So I'm currently in my second year doing biomedical engineering. I want to study physics in grad school, but am at an impasse. I can't do a physics minor because there is no space in my schedule, and I can only petition one physics course to fulfill my engineering electives. So I am debating...
I am first time using a contactor. I have a 3-phase contactor with me, Need to switch on and off without any load connected. It has two auxiliary terminals A1 and A2, for just to turn on how it should be connected?
This is actually Java!
My current problem: I need my switch statement to show only the given information for each selected shape.
For example when I click "circle" on the drop down menu, I want my switch to ask for the radius only while showing my compute button and answer.
When I click...
1. I thought that when switch was closed, voltage at the right side of switch was 0 and long time after the switch is open, the voltage at the right side of the switch becomes 0.
2. After the switch is open ecause of the inductor, voltage at the right side of the switch is εL = induced emf
So...
Hi,
I'd like to use Switch with an integer partition of a number. For example, if n=4, then I define the partition as:
monodromyTypes = IntegerPartitions[n];
this gives:
monodromyTypes={{4}, {3, 1}, {2, 2}, {2, 1, 1}, {1, 1, 1, 1}}. I'd then like to set up a Switch depending on what the...
I am working on a switch mode psu in step down configuration with the key components being:
LM2592 (adj) http://www.ti.com/lit/ds/symlink/lm2592hv.pdf
530-PC-24-1000 http://www.mouser.com/ds/2/643/PC-594199.pdf
GSIB-25 http://www.vishay.com/docs/88646/gsib25xx.pdf
Using a slightly modified...
Hello,
My question is simple. Let's suppose you have an electromagnetic coil with a magnetic weight in the center of it. This coil is energized, and the weight is lifted up vertically.
Now, my weight is 30 kgs. I want to lift it to a height of 1 meter. How do I calculate how much power is...
Homework Statement
See attached image for circuit diagram and givens.
The switch has been closed for a very long time.
a) What is the charge on the capacitor?
b) The switch is opened at t=0 s. What current initially flows?
Homework Equations
V = IR
Q=CV
I=I0e-t/(RC)
The Attempt at a Solution...
hey guys,
to be hounoust I'm kinda ashamed to be asking this, but a simple thing is turning out far less simple then anticipated and i don't seem to be able to find the solving clue.
i am in the situation that i want to switch on and off two mainboards (one pc mainboard and one soft-switch...
I'm a sophomore math and physics double major, and I'm losing interest in physics. I still love math (like seriously love), but I honestly don't see myself working in a physics lab or anything. A lot of the modern physics stuff really does not appeal to me at all.
I currently plan on switching...
I'm looking into the design of the control circuit for the mosfet. If I know the output voltage and input voltage then I can find the duty cycle required. I found this schematic that uses feedback
Source
https://www.maximintegrated.com/en/app-notes/index.mvp/id/2031
Why would I need feedback...
Homework Statement
Initially switch is at 0.
At t = 0 seconds switch is put at 1.
After 1 time constant switch is put at 2.
Find equation for current for t > 2[/B]
Homework Equations
current through inductor tries to remain constant.
i(t) through inductor in series RL circuit is i(t) = [...