Counter Definition and 213 Threads

Homework Statement I have to define part of a method that will take in a String, segment the input into words, keep track of how many of each word there are in the string, and then return a [FONT="Courier New"]HashMap<String, Integer> that shows how many of each word there are in the string...

In the example diagram I have provided how can the counter EMF produced by the conductor moving through the magnetic field be determined? I am assuming the field is uniform and that the velocity and current in the wire is constant. My logic tells me that there is no net flux cut by the...

Are you able to predict precisely the count rate for a radioactive material? Why or why not?

Hi, I have a question about back emf So, my understanding of back emf (\epsilon_b=-L\frac{dI}{dt})is that its the counter voltage that's induced by change in current, whether it be from a battery or magnetic field (\epsilon_0). We can model this as an LR circuit where \epsilon_0 +\epsilon_b=IR...

Hi people, please excuse me if this is the wrong forum to ask, I am new. I want to build a cheap DIY trip wire that records how many times it is set off. If I could use some sort of laser to be more discrete that would be a bonus (and just cooler). Also if it is possible to record the time that...

I know that the conversion time for an adc counter ramp is the time between the start and stop of the signal conversion, but how do i calculate this time? Also is the conversion time for the bi-directional counter ramp adc 1/2 that of the uni-directional counter ramp adc? Could someone kindly...

Homework Statement design an up down modulo-16 counter. use grey code state assignment, when x=1 the counter is to count up. when x=0 the counter is to count down. when the terminal cont of 15 is detected and the unit is counting up or when the terminal count of 0 is reached and the unit is...

Homework Statement A meter stick rests on two counter-rotating wheels. The left wheel rotates clockwise while the right wheel rotates counter-clockwise. There is friction between the meterstick and each wheel. The meter stick begins off-center to the right. What is the resulting motion of the...

Homework Statement I need two counter examples, that show the following two theorems [B]don't/B] hold: Let X be a topological space. 1. If from the closeness of any subset A in X follows compactness of A, then X is compact. 2. If from the compactness of a subset A in X follows closeness...

First post! :) I am building a Geiger counter with this circuit: http://www.pocketmagic.net/wp-content/uploads/2011/03/geiger-simple-1b.jpg in the blog the author used a regular EI transformer from a power supply, but I tried disassembling them and broke the ferrite core 4 time now, so I...

Homework Statement Hi all, First post so please go easy :smile: I am designing a Dumbbell support that presents the Dumbbell to the user in the correct exercise starting position (1. Shown on the image.) . The problem I am facing is the counter balance to the support. The Dumbbells range from...

Hi, I am trying to make a digital clock using a synchronous counter. Can anyone please provide me with a proper circuit ? I am having some problems when designing it myself. Thanks.

Homework Statement structure or behavior VHDL code of a 5-bits binary counter with a sync. load signal to preset the counter to a specific initial state. the output of the counter (Q0 to Q4) are connected to a binary decoder that shows the state of the counter.Homework Equations The Attempt at...

Hi...can anyone tell me whether there is a decade counter which has only 1 input, 10 outputs and an up/down clock?

Homework Statement in the given figure, vectors u and v each have a magnitude of 55 pounds. Find the magnitude and direction of the force w needed to counterbalance u and v? So the "figure" is pretty simple... it shows a line labled North and south and vector u is pointing 45 degrees in the...

Does that mean if there were zero (or close to zero) "noise" ...faster than light (flt) transfer of information would be possible? i.e. if the experiment was conducted in some dark & quite region of space-time...where only the entangled pairs were allowed strike the detectors (Ds and Dp)my...

For any natural number a and b, with b > 1, two natural numbers x and y can always be found such that b^x - b^y is divisible by a. Until now, with many tries of a and b, I have always found corresponding x and y. I would appreciate if somebody could give me a proof or a counter example.

I am solving for the surface area of a helical ribbon that I represent as a ruled surface, the curve being the helix and the rulings being in the vertical \sigma\left(t,\varphi\right)=\left(\begin{array}{ccc} r\cos t, & r\sin t, & \omega t+\varphi\end{array}\right) I solve for the terms in...

I have what I believe is a simple question about the single photon (at a time) double slit experiment. This experiment does not use a coincidence counter correct? I understand that one, or more, is used for entanglement experiments, but is one necessary to determine an interference or lack of...

Homework Statement Hi, I need to design a simple frequency counter to measure the frequency of a square wave input (hence signal conditioning is not needed for now). I have understood the concept that the counter needs to count the input pulses for 1 second and display them on a 7-segment...

Homework Statement I'm a bit at a loss here for a particular assignment we got for one of our labs. I've been using a certain method to derive the k-maps for some circuits, but for this particular one, it didn't really work out too well for some reason. We built and implemented a 4-bit...

Do we need a coincidence counter (for correlation) in delayed erasure?...in case of repeating the same experiment many times (with one photon at a time) the same way In the DCQE experiment such as the one listed below http://grad.physics.sunysb.edu/~amarch/ Notice the polarizer...

Hello, I have constructed a 25 Led counter and am having a little trouble. I have cascaded 3 4017's with a 4011 according to how the data sheet shows. I have added a pushbutton along with a 4001 to debounce for a clean count. I get a good clean count with one push of the button from LED 1 to LED...

Homework Statement I'm trying to derive the \epsilon - NTU Expression for a double-pipe counter flow heat exchanger. I know what I need to do the only problem I am having is: I don't know how to algebraically go from ln( \frac{\Delta T2}{\Delta T1} ) = -UA ( \frac{1}{Ch} + \frac{1}{Cc} )...

I'm having a problem with providing counter examples when disproving a statement. For example A - (B U C) = (A - B) U (A - C). The solution given was A = {a}, B = {a} and C = empty set. My question is how can you work this out - i was told it's possible from the Venn diagrams but I'm not...

Homework Statement [PLAIN]http://hh7.net/Apr1/hh7.net_13016941501.gif Homework Equations these statement are false and i need counter example for each one The Attempt at a Solution for(ii) i can say that f(x)=x2-4 on [-6,6] for others i need help

Can you provide one to show a separable complete boundd metr. space X is not always seq. compact.

The title says it all. Please be detailed, the question is 6 marks. Thanks.

Homework Statement Prove or give a counterexample: for all x > 0 we have x2+1< (x+1)2\leq 2(x2+1)Homework Equations The Attempt at a Solution I used my calculator to do the graph of all 3 functions and saw that the statement was always true (at least for x>0). So I couldn't see another proof...

hi, I wish to design BCD up and down counter circuit for my mini project. I planned to use IC 74LS192. Unfortunately i can't able to get this IC. There is any BCD counter ICs are available with separate up and down counting clock signals. Because i got some ICs for up and down counting which...

give counter examples to disprove the following statements: a) a real valued odd function cannot be strictly monotonic b) a real valued periodic function must be odd or even c) a real valued monotonic function cannot be even a) sinh(x) ?? b) c)

Homework Statement 1)Design a counter that counts from 0 to 23 Then resets? 2)design a counter that counts as shown below: (1)to(5)to(7)to(8)to(2)to(3)to(6)to(4) in another way: 1-5-7-8-2-3-6-4Homework Equations I didn't know weather to use: 1)5-bit synchronous binary counter 2)5-bit...

[PLAIN]http://img30.imageshack.us/img30/3306/counterty.jpg Is this an asynchronous down counter, or is it nonsense? (Assuming all J and K inputs are connected high) Trivial question, I know :-)

[PLAIN]http://img713.imageshack.us/img713/853/98302269.jpg So I included the waveform I drew in the picture. The first one is the clock pulse, the second is the output from the T-flip flop on the left, and the third is the output from the T-flip flop on the right. I'm really not sure if this...

Homework Statement Fig (a) is a counter, fig (b) is a divide-by-N counter (0 < N < 16). The 4-bit input ABCD is (I think) what the counter counts to before resetting. Questions #1: For circuit (b): Say you want a divide-by-9. Why is it that to do this, the 2's complement of 9...

Can someone explain to me or refer me to a site that explains how to use a binary counter such as the 74LS169 4 bit up/down binary counter? I'm not sure what all of the inputs do.

Hello, I want to ask, I have a counter 74193 or 74191, and I want to make it counts 3 clock cycles.. any ideas how to do? we suppose to use timer 555 right?

Homework Statement X and Y are two closed non-empty subsets of R (real numbers). define X+Y to be (x+y | x belongs to X and y belongs to Y) give an example where X+Y is not closed Homework Equations The Attempt at a Solution i tried X=all integers and Y=[0 1] but that didnt work out. i know...

If we get on a train and time the train’s travel over 1000 meters, we can calculate the train’s velocity; v = dx/dt But if our watch is running slow, we will measure incorrectly and think the train was going faster than it really was. v’ = dx/dt’ We know that when something moves very...

Non-convergence counter example?? (This question occurred to me in the context of quantum field theory, but since it's purely mathematical, I'm asking it here...) Consider the universal vector space \Xi of arbitrary-length sequences over C (the complex numbers). Denote \delta_k ~:=~...

I need a device with something like a 4-digit LCD or LED display which counts the amount of times its input and output contacts close. Basically, 1 count for each completed circuit. I was told things like these exist and are cheap, but don't know what to call it. Thanks in advance!

Hi guys, I have a scenario here; let's say we have a exothermic reaction and a endothermic reaction going in co-current flow reactor (separated by a thin wall to facilitate heat transfer). At steady state after some time, from the concentration profile, we have the endothermic reaction going at...

I'm reading a QFT text right now and to fully understand the physical perturbation theory method I would like anyone to suggest a refrence or supply an example of a calculation using the physical perturbation theory: As an example to start a discussion consider. L = \frac{1}{2}((\partial...

Homework Statement In a local bar, a customer slides an empty beer mug down the counter for a refill. The bartender is momentarily distracted and does not see the mud, which slides off the counter and strikes the floor 1.4m from the base of the counter, If the height of the counter is 0.860m...

One of the first expressions that I came across in studying SR was that it was Counter Intuitive. In particular this expression was used to define the relationship between local time and the time measured by a 'moving clock'. It seemed to be thought that newcomers to the theory would...

hi there... I wanted to ask about a way to cascade or let's say connect two sets of 4-bit flipflop JK counters together.. I want to create a circuit that is an up-down counter from 0 to 99..but as it is known, its difficult to use 8 inputs ofcourse.. so the best way is to have two sets of 4 jk...

Hi, Let's say i want to make a binary counter using jk-flip-flops that counts 1,3,5,7,1... Then i'd use the excitation table for the jk-flip-flop to determine the next state. The next step would be to use karnaugh-maps to minimize the j and k columns. My question is: Do i need to...

Hi! I want to design a data transmission circuit (transmit 7 bits data with 1 start, stop, and parity bit) by using gates. The part I have done is CRC and parity.Now I want to design the transmission part, I want to use a counter to count the time of data division until 8 then transmit the...

Can anyone explain the following (the capitalized text)? "The ions of the quenching gas reach the cathode before the principal gas ions. When they reach near the cathode, THEY CAPTURE ELECTRONS (secondary?) AND BECOME NEUTRAL MOLECULES. FOLLOWING NEUTRALIZATION, THE EXCESS ENERGY OF THE...

I'm wondering if anyone could point me to a reference that explains how commercial digital geiger counters convert from the natural counts/sec unit to units of mR or uR/hr?