Switch Definition and 555 Threads

Homework Statement This is the circuit diagram I am working with: There is actually a switch under C3 that I didn't draw. Initially, the switch was set so that the red dashed line was part of the circuit and the green dashed line was not (so C1, C2, and C3 charged but C4 did not). Then...

I have an M.S. degree in electrical engineering from Univ. of Minn. and have been a practicing engineer for almost 30 years now. I've about had my fill of engineering and I'm seriously considering switching career to teaching high school physics and math. Assuming for the moment I have...

Here's the rundown of things: I've been wanting to be a computer engineer for years and years, but now, I'm just finding it difficult to understand math, specifically trigonometry (not even calculus yet!). I know for a fact that I'm just really awful at...shapes(?), so geometry and trigonometry...

Optical fibres are used to transmit light from one place to the other along curved path in a more effective manner. The optical fibres consist of thousands of strands of a very fine quality glass or quartz of refractive index about 1.7 or so. The thickness of a strand is about 10-6cm. The...

Homework Statement Image Homework Equations The Attempt at a Solution for t > 0: α = 1/2RC = 250 ω = 1/√(LC) = 150 ω < α overdamped s1 = -50 s2 = -450 vc(t) = Ae-50t + Be-450t dv/dt = -50Ae-50t - 450Be-450t for t <0 : Vcap = 12(1/6) = 2 V (open circuit) Iind = 12/6 = 2 A (short...

can MCB be used as normal on/off switch?

i am well aware that the job field may be narrower in view but would this be a smart move? i didn't do too well the past two semesters and I am being forced to switch majors. the reason i didn't do well was because of a complete lack of interest and effort on my behalf. I couldn't stand...

Hi all, I would like to make a switch for an AC signal (on off ,ie, high impedance and low impedance). The switch should have less than 1 ohmn impedance. The signal can range from 1-100Khz and the signal will be 50Vrms. I tried to use mosfets, but they do not block the signal completely...

Hi all. Hope you can help me out. I'm making a battery powered electronic cigarette and I need a momentary switch that is rated above 20amps at 8,4v. There tons of switches out there but the ones I like are rated at 3A/250VAC or 2A/ 36V DC etc, do these switches have a higher amp rating if...

Hello everyone, I've read about green day when government says to switch off appliances for an hour in evening. But if everyone switches off appliance, then where will all that current go? We cannot stop generator so quickly. It's like a dam is giving water to three pipes, in full...

Homework Statement 2. The switch in the circuit below had been closed for a long time before it was opened at t = 0. Given that Vs = 10 V, R1 = 20 kΩ, R2 = 100 kΩ, C1 = 6 μF, and C2 = 12 μF, determine i(t) for t ≥ 0. Homework Equations The Attempt at a Solution For this problem...

I have once read that if a voltmeter is connected across an open switch in a circuit, the emf of the source is shown on the voltmeter, because this connection completes the loop, making a tiny current flow through the circuit, and since the voltmeter has a huge resistance, the entire voltage...

I need to know about optical switch for my optoelectronics course for physics majors. So far I only know its a switch which is controlled by light. I tried to search net but couldn't find any thing. Is optical switch have another name?

I applied to Texas A & M as a junior transfer student with my first major choice being mechanical engineering and my backup being industrial engineering. I was admitted under industrial engineering, but I am pretty sure I wouldn't enjoy that field. If I choose to attend TAMU as an industrial...

why do we require transistor switches ...I read one related forum in that it was written transistor switches can be triggered using electrical signals. TRUE.but if at all u want to off the ckt give zero signal(may be through microproccesor) to the o/p directly why do you want to increase your...

Hi guys, For a science experiment I've got to measure the power consumption of my circuit of a 100W incandescent light bulb connected to the mains AC, with a dimmer switch to vary its brightness. I was planning on just using one of those plug-in energy monitors with a digital display but...

please can you help, explain me in easy way this circuit http://obrazki.elektroda.pl/2237673700_1387888073.jpg normal must be swith in position A q1 on q2 off q3 on switch in position B q1 off q2 on q3 off

Stay or switch high schools?! Math and science are my favorite subjects. I like to challenge myself and take the hardest classes. However, my school doesn't have AP Calculus BC or AP Physics C. I'm currently a soft-more. Should I switch schools, or just take those classes in college? Thanks

Hey folks - Question. I'm working on a secret door disguised as a bookcase and I'm looking for some help from a curious and knowledgeable electrical engineer about a clever way to make the lock open. The desired effect is for the opener to touch two brass busts on the bookshelf...

A circuit has n switches, all initially off. In order to be able to flip the ith switch, the (i-1)th switch must be on and all earlier switches off. The first switch can always be flipped. Find a recurrence relation for the total number of times the n switches must be flipped to get the nth...

I'm wondering what the name of a switch that alternates between two states only when depressed. An example would be a flashlight, where if you click it once, it turns on, and if you click it off, it turns off (no need to hold down the button to get a continuous light).

I need to hook up 8 electromagnets and make them turn on and off to a pre designed pattern. I have no idea how to get something to turn on and off in a programmed sequence. I'm sure there are probably ready made programmable switches that come with software but I don't know. In any case I...

So I'd like to pulse a current to a load from a transistor. I can use a µ-controller to trigger a transistor. The µ only has a minimum pulse length of about 100ns or greater. But I would like to have the current flow through the transistor for a much shorter pulse length than 100ns. Maybe a...

When an electrical circuit is opened or closed there is an arc between the terminals/buss that the switch or breaker is connecting or disconnecting and the arc is greater depending on the amount of voltage. My question is, is the arc greater when there is a resistance/load on the circuit? I'm...

In Home Wiring the Switch that is used to tun on and off just one light is called a S.P.S.T Switch. Now when you have one light that has two Switchs that can turn it on and off the Switchs are 2 way Switchs. But are they called S.P.D.T Switchs?

Homework Statement When switch S in the figure below is open, the voltmeter V of the battery reads 3.68 V. When the switch is closed, the voltmeter reading drops to 3.50 V, and the ammeter A reads 1.80 A. Assume that the two meters are ideal, so they don't affect the circuit. Find the emf...

Greetings. I'm making a high power boost converter, supposed to deliver constant current at 15-50V from about 12V input. 100KHz frequency. There are problems, however. There was a lot of ringing at the switch node - meeting point of the diode, inductor and MOSFET. 5.8Mhz clear decaying...

I've been looking around for formulas on how to calculate different aspects of DC motors and buck converters such as average current. The reason is that I'm about to pick switch frequency for a motor, and don't know what characterics I can expect if I alter the switch frequency. Papers and...

"dynamo-technology switch"? From this article: NBC news article What is a dynamo-technology switch? Why were they not using another type of switch? Thank you.

Hey guys I am working on a safety system for the brake system and I am looking for a detent switch that can be used to stop the system from working, ie the engine and fuel pumps an dother electronic controls in the car. The switch has to be SPST and should keep the system 'off' until the...

I started working for a multinational FMCG after graduating in Mechanical Engineering. With one year as of now in it, I somehow feel this is not a path to take for lifetime. I am paid well and my work is mix of management and engineering (Since it's the maintenance and I am the process owner)...

i was messing with a friend of mine, constantly switching his bed lamp on and off; he said that's how light bulbs get burnt out. I don't understand the physics behind this. All that's happening is an alternating on and off AC power going through the light bulb. is it the arc at the switch site...

Hello all, Long story short: I'm modding a Netbook PC; I'm powering three different sets of LEDs from three separate USB power sources. 1. How can I create one master power switch for all three circuits? 2. Would hooking all three circuits up to one switch in parallel burnout my USB ports...

Hi I would like some advice on what you think I should use as a passive switch for my NPN or MOSFET transistor. I am trying to PWM pulse with modulate an electromagnet with a 12V 3.6A battery and I want to have a passive switch. I have tried to use photo interrupters in the past but I am not...

I have a N-ch Mosfet load switch that connects to a WiFi module on a circuit board. When the switch is turned OFF, I still see a voltage of 1.4V at the load. Ckt attached. I decreased the bleed resistor from 1k to 100 ohms. The off voltage decreased to 1.1v. This doesn't happen with other...

Hi, I was going through the web and was reading about this swap, however I want to make sure on a few questions I still have and was told I could get good advise in these forums. So I was going to go ahead and change a switch for a power outlet for convenience, but then realized it might...

Homework Statement Hi all, My question is: In what kind of device the enclosed schematic can find an application? The bipolar switch has two positions U and u- which are for upper position and D and d- which are for down position. The main question is on what kind of equation the voltage...

How to design a Output enable ckt (like the ones in logic gates and buffers) using a simple component like BJT or FET.

Switch to scale factor "time" (universe its own clock) In a sense the universe is its own clock and the pointer-hand is the scalefactor, as in: "when distances were 0.1 what they are today" "when distances were 0.3 what they are today" "when distances were 0.9 what they are today" For some...

Homework Statement Initially switch is at A, and C1 is fully charged (batter=12volts). C2,C3 are initially uncharged. Then switch is moved to B and the charge is redistributed. What is the voltage across C1? [Answer: 8.00volts] What is the voltage across C3? [Answer: 2.67volts]...

I am pretty much satisfied with the example of a rotating shell example 5.11 pg 367 griffiths electrodynamics.on many ocassions he chooses cartesian coordinates before integration (see 5.10 too) , integrates and finds w×r along y direction .then he manipulates w×r, and writes it down in...

This is not really a homework question. Just a question regarding the normally open (NO) and normally closed switches. For an NO switch, if the button is pressed (not open anymore) and then the button is released, is the switch still in the "not open" state or does it go back to the open state?

Homework Statement When the switch is closed, Potential drops to 40v across C1 & C2(Parallel series). Find the Capacitance of C2 Homework Equations Before switch is closed C1=300uF and holds a charge of Q1=3e4 uC V=100vAfter switch is closed V'=40vThe Attempt at a Solution V1=V2 So...

I am trying to make a sound activated linear actuator to open blinds when my alarm goes off. There are a couple concerns I have; Will the switch be triggered by a loud alarm clock? and would there be a way to have another switch to close the blinds once they have been opened, something like a...

Homework Statement SPST switch closes at t=0. Find vC(0-) and iL(0-), iC(0) and vL(0), and vC(infinity) and iL(infinity).Homework Equations The Attempt at a Solution kind of basic circuit, i know, but i just wanted to check my answers in case i did something wrong. At t=0- : capacitor acts...

Hello everybody, I am stuck with a circuit that involves voltage controlled switch. Homework Statement The switch is controlled with a square wave generator, Vs1, whose frequency is 100kHz. As far as I know, switch is off when source is on positive phase and vice versa. Therefore, I only...

My problem: There is an LED and a switch. When the switch is closed, I want the LED OFF. When the switch is open, I want the LED ON. What is the simplest circuit I can build to make this happen? The power source can be either AC or DC, whatever is easiest. Thanks!

Hi, new to the forums. Sophomore in college, Nuclear Engineer in training. Nuclear Engineering seemed tempting for a few reasons: Engineering = $$ and Nuclear, well I love nuclear physics and chemistry so why not! Now what I found out: What nuclear engineering is NOT: Quantum mechanics...

Homework Statement Find v(t) after t=0, when the switch moves up need to know if i did this right.. V(C1)=V(C2)=10V (this is same for t=0- and 0+) V(infinity)=0V (no voltage source) T=RC=100k(ohm)*(4uF)=0.4 sec. (i got the 4uF by putting the 2 caps. in parallel with each other, because they...

Homework Statement Please look at the attachment. The part I am having problems with is part C Homework Equations time constant = RC Q = Q0 e^(-t/RC) The Attempt at a Solution I don't understand why the circuit is equivalent to the 4 ohm resister with the 18 ohm resistor in series so that...