Questions tagged [time]

Time cannot be created, but it can be measured by using common references. The oscillation of the cesium atom, or a pulsar, can be used in our lifespan, but neither one is steady forever. We can create 'instances' of time with tuning forks and electronic oscillators. By creating them we define them in terms of 'increments' of time. Those deemed to be laboratory grade become our reference devices for measuring time and frequency, the reciprocal of time.

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

What does hₖ[n] mean here?

Is the impulse response different from the output y[n]? Is the input x[n] all the delta function at different values of n? From Signals and Systems by Robert Oppenheim, Linear Time Invariant systems
0
votes
2answers
50 views

Is this the best way to make a timer auto-off feature for a CPU fan?

This circuit is outside of a PC simulate this circuit – Schematic created using CircuitLab I want to make a fan that shuts off after a preset time depending on the capacitor value. The button ...
1
vote
3answers
200 views

How are system clock and oscillator frequency related?

My question is given a, for example, a quartz oscillator on a MCU board, how is the system clock generated? I'll break down this question into several parts below: I always have the impression that ...
0
votes
1answer
76 views

Reliability of Sampling Rate vs Absolute Timestamps

I am building a system with multiple sensors and I want to sample the different sensors at different rates. For the sake of an example, I am using two MAX30102EFD-T sensors. One of the sensors I want ...
0
votes
0answers
53 views

Inductors voltage substitution from 2 independent equations

We have this circuit: simulate this circuit – Schematic created using CircuitLab The current through the inductor IL = Io(1-e^(-R*t/L)(1): Now there is an equation VL = -L*dI/dt(2) my question ...
-1
votes
2answers
48 views

What is the uncertainty of the Analog Discovery oscilloscope?

I'm an electrical engineering student and I have to measure the Slew Rate of an opamp (and most importantly its uncertainty). I created a simple voltage follower circuit and I'm using the Analog ...
3
votes
1answer
53 views

State Space Clock Model & Control

I was hoping to get some help understanding a state space model that I have found in time and frequency literature. The literature pertains to a discrete-time model of a steered clock. A phase ...
1
vote
3answers
209 views

How does the 4th satellite in GPS know the time offset?

Going through the working of GPS technology, I came to know that at least 4 satellites must be visible to solve for the location with considerable accuracy. Going through most of the resources, I can ...
0
votes
2answers
54 views

What is a “discrete time controller”?

I'm reading a paper, and the first sentence is: Most dynamic systems are controlled by discrete time controllers What is a discrete time controller ? Thanks
0
votes
2answers
167 views

How to use a CSV file from an oscilloscope for further analysis

I saved and opened this data from my oscilloscope: How to plot the real scale waveform data? Do I have to multiply it with vertical scale? And what about the time? What to do if I want to plot the ...
0
votes
0answers
31 views

Best way to run current for certain amount of time

I have a circuit set up that requires around 5 Amps of current to run but I need it to only run for a specific amount of time. The circuit is activated when I press a button and I want some tool to ...
0
votes
0answers
22 views

Comparison between the same signal from different sensors

If I have PPG (plethysmograph) signals from sensors that are positioned in different locations along with their corresponding power spectrums, how to determine systematically and accurately the best ...
0
votes
3answers
106 views

DIY reference clock jitter / Allan deviation measurement

I am considering doing some recreational timing. I have few OCXO's, GPSDO, Rb source - but no way to compare their stability / jitter. Majority of sources are around 10Mhz. Is there any DIY-friendly ...
0
votes
0answers
59 views

How to sync time between two devices (<30m apart) with a sub milisecond accuracy? (think PTP)

So my task is to detect the source of banging in a metal tube (picture radiator pipe). The idea is to put two mics to the ends of the tube and measure time differences when they hear banging. The tube ...
1
vote
1answer
63 views

Fourier Transform Time Scaling Property using f (frequency) or w (omega - angular frequency)

The time scaling property for a fourier transform is as follows: My book shows this property in terms of \$f\$; however, my instructor likes to use \$\omega\$. I have also seen this property written ...
0
votes
0answers
35 views

A problem with designing a time register

I'm on a project where I need to design a time difference register. In a time register the time information is first converted to voltage, which is stored in a capacitor. Later, when we want the ...
1
vote
2answers
100 views

Wireless Time Synchronization Project

I am part of a team project involving baseball where we would like to determine whether a runner stepped his foot on the base (first base, for example) before or after a fielder (the first baseman) ...
1
vote
1answer
65 views

Inductor Voltage and Current After Switches Open and Close

I was given this problem where switch s1 and s2 are opening and closing at different times. I have already solved for the voltages and currents, but now I need to plot vL and iL at each time. My ...
0
votes
0answers
90 views

Why is Δt constant in phase shift measurement?

I would like to ask for some help with phase shift plotting. To be precise, with time delay between two waveforms. I am measuring two currents using an oscilloscope. channel A (blue) is my current ...
0
votes
1answer
70 views

The constant time value for an electronic device [closed]

i am working in a data science project that require certain information about electronic devices. So I know that for each electrical circuit there is a permanent regime and a transient regime and ...
0
votes
2answers
53 views

Time interval quantized?

We have a capacitor fully charged with some voltage. At t=0 we can find the current. This current will change the voltage of the capacitor. However the information of the change of the voltage of the ...
0
votes
1answer
42 views

time axis confusion in signals and systems

I am learning signals and systems and we are given a impulse response swhich is discrete and from -5 to +5 on X axis. I do not really understand that it has a negative part as everything starts from 0 ...
0
votes
0answers
45 views

Using 32 bit variable in microcontroller to find elapsed time

I am trying to establish a time line (updated by soft counter) which would never end within embedded system product lifetime. For this purpose I think of using a 32-bit variable i.e. ...
0
votes
0answers
42 views

Calculate time energy is stored in capacitor

I have this problem: I've calculated A) to be 8 nJ, and my Vc(0) = 4 V and Vc(∞) = 0 V. I tried using the wc(t) = 1/2CVc^2 formula to calculate the time when the energy of the capacitor is 1 nJ. ...
0
votes
1answer
44 views

How to discretize value like EDF ( or other electricity companie )

I make a solution using some automate like : A9MEM2050 ( Shneider ) ( and more advanced, so i have a lot a different value , that include rpm, psi, armonic, etc ...) Every automate send a value every ...
1
vote
0answers
43 views

timestamp generator register location on Cortex-M4 (PSELCTRL CNTCR)

I am trying to find the location of the register where the timestamp generator can be enabled on a Cortex-M4 processor. In the CoreSight SoC Technical Reference Manual on page 3-210 it is mentioned ...
0
votes
2answers
151 views

Calculate power on time of a buzzer

I would like to use a 5v active piezo buzzer to beep for a second or two. When the relay is on NO the capacitor will charge from the dc source and when the relay is on NC the capacitor will discharge ...
0
votes
1answer
133 views

Are consumer systems able to measure nanosecond timings?

Following the theft of my brother's car (a modern Audi Q-something), I got interested in how contemporary cars are protected. The authentication of the key to the car is dreadful (I work in ...
0
votes
0answers
298 views

PPS Timer on STM32

The MCU used is a STM32F042 which is clocked by an OCXO oscillator (Abracon 10 MHz - 20 ppb). The subject of this thread is to get the best accuracy on one PPS Timer. For my application, I need to ...
0
votes
0answers
39 views

Time Domain Analysis with Vector Network Analyzer

I have done some measurements with a VNA in time domain (by using the transform operation of the instrument). Precisely, I have selected the measurement of S11 (reflection coefficient at port 1 of the ...
0
votes
2answers
73 views

How do I calculate the capacity of a capacitor using measurements of an experiment?

I build this circuit in an experiment During the experiment I got these readings: ...
0
votes
2answers
645 views

Is charge batteries in series faster than in parallel?

I would like to know if charging 7 lithium-ion batteries in series with BMS 7S are faster than simply charge them in parallel. Please for your advice, thank you!
0
votes
0answers
48 views

How to generate time delay when input frequency is high?

Im trying to generate time delay for my gate drivers for a project im working on. But the issue is at lower frequencies my circuit works fine, as I ramp up the frequency (upto 250Khz) the output goes ...
0
votes
1answer
42 views

Current when switching on with inductance. Role of Reactance?

When switching on the current through a coil it can be described as: \$ I(t) = \frac{U}{R} \cdot (1 - e^{(-x\cdot R/L)}) \$ For a sinusiodal current the complex resistance for a circuit with ...
0
votes
2answers
80 views

NTP Time calculating

I have this code and i use in my device. ...
9
votes
8answers
495 views

Measuring the activation time of a solenoid

I'm trying to measure the activation time of a pull-type solenoid. When the solenoid doesn't have a load connected to it, you can measure its activation time through the current it consumes. At first,...
0
votes
1answer
83 views

Output Capacitor Voltage Holding time during dropout

I have a buck converter. Vin = 12V Vout = 5V Iload = 0.5A I have one dropout requirement. ...
0
votes
0answers
45 views

Calculation on gate charging [duplicate]

I would like to calculate the response time of the PMOS cicruit in this ciruit. But I have some troubles about the gate charging. I'm trying to use this: https://www.vishay.com/docs/73217/an608a.pdf ...
0
votes
1answer
398 views

How to calulate mosfet response time with load?

I would like to calculate the response time of a PMOS circuit and of the circuit Could you tell me how to do it? I'm using this transitor. https://www.infineon.com/dgdl/Infineon-IRFR6215-DS-v01_02-...
1
vote
1answer
76 views

Real time spectrum analyzer and Fourier Transform

I am studying spectrum analyzers and a doubt came to me about real time spectrum analyzers. Suppose you have a signal in the time domain: in order to calculate the Fourier Transform, you need to know ...
0
votes
0answers
78 views

Does the profile of phase-noise power spectrum density (PSD) vary with time?

I will promptly provide any detail or revise my question aimed at any feedback. Does the profile of phase-noise power spectrum density (PSD) vary with time? The conclusion may be that it won’t ...
0
votes
1answer
652 views

RTC DS3231 get reset

The RTC module ZS-042 get suddenly reset and show default values (2000/0/0) with no possibility to change it no matter what. The reset can occur after uploading a new sketch (I'm using ESP32) or while ...
1
vote
3answers
251 views

Is there a low voltage LED alternative?

I am trying to create a tiny little watch that is supposed to run off a coin cell (because it is so tiny) and basically just a microcontroller with a 30ppm 1Mhz oscillator that counts upwards. The ...
0
votes
0answers
106 views

High precision timekeeping

Hey I'm looking for suggestions for implementing a very high precision timekeeping device. I need to record independent signals in multiple devices and then time match them to an accuracy of about ...
0
votes
1answer
127 views

Phototransistor and Photodiodes capacitances when some in an array sense light

I'm using phototransistors to sense low speed data (about 7 bits a second). With one phototransistor and a 300K resistor, I found my sweet spot and can transmit correct data with lazer. I find if the ...
0
votes
2answers
104 views

Detecting IR sensor at higher speed

I made a circuit which selects one of 4 sensors and determines if a valid data stream is present on that sensor and counts the number of times data is valid. I narrowed my problems to hardware. In ...
1
vote
1answer
2k views

Finding the time constant of an RL circuit

I've the following circuit: simulate this circuit – Schematic created using CircuitLab And I've to find the time-constant of the voltage across the inductor. I did the following: The voltage ...
6
votes
3answers
2k views

Discharge time of 12 V 8.4 Ah at 5 mA

I have a motorcycle battery rated as 8.4 Ah (20 HR). It also says 8 Ah (10 HR) and I am not sure what the difference is. Anyway, I have a GPS tracker fitted with a rated ...
1
vote
3answers
1k views

z-Transform Methods: Definition vs. Rectangular Rule or Tustin's Rule

The definition of the z-transform is defined as \$z = e^{sT}\$ where "s" is complex frequency for continuous-time systems and "T" is the sample period. Why are rules such as the forward rectangular ...
0
votes
2answers
433 views

how to calculate the tpdhl / tpdlh for any given circuit

i am struggling on calculating the tpdhl / tplh i dont know how to calculate is there any algorethim for the way we calculate the time propagation high to low etc.. several questions asking to take ...