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.

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48 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 ...
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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 ...
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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. ...
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Measuring time propagation of NAND gate with different inputs

I want to measure time propagation of the signal in an NAND gate and I'm getting confused about how I should measure it. Should I take a point in time where both of the inputs changes simultaneously ...
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41 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. ...
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Determine speed or time to reach, using ratiometric hall sensor?

Below is the setup, it consists of a ratiometric hall sensor (SS490 honeywell) i.e similar to a linear sensor, and a magnet (south pole facing sensor). The initial distance that they are separated is ...
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41 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 ...
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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 ...
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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 ...
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132 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 ...
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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 ...
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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 ...
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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: ...
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2answers
228 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!
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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 ...
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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 ...
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Insertion loss measurements, frequency sweep vs measuring points with a constant driving frequency

I have been modelling a surface acoustic wave delay line, and am trying to clarify what I am seeing in the different models and whether this is applicable to what would occur experimentally. In the ...
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76 views

NTP Time calculating

I have this code and i use in my device. ...
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8answers
358 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,...
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1answer
66 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. ...
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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 ...
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188 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-...
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Time period of output in relaxation oscillator circuit

I'm an electrical engineering student, and have spent the last 4 hours trying to figure out the time period of the output of the circuit below (in terms of the variables shown in the image). So far, ...
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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 ...
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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 ...
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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 ...
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3answers
171 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 ...
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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 ...
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1answer
73 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 ...
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2answers
87 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 ...
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1answer
515 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 ...
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3answers
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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 ...
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485 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 ...
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2answers
259 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 ...
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1answer
49 views

Byte-Banging 2 8051's using port addresses

Currently I have two microcontrollers setup in which entire ports are connected to each other (P1.1 connected to P1.1, P1.2 connected to P1.2, etc). I also have two pairs of extra GPIO pins connected ...
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135 views

“Leeching” clock information from cell towers

I understand that cell base stations transmit very accurate time signals among other things. Do you need a SIM card and an account to receive this information, or is it something you can "leech" with ...
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1answer
51 views

Programmatically determine the lowest waiting time for character LCD display

I made working code in an older microcontroller for a character based LCD that's based on the HD44780 chip. My code stops execution of everything else every 70uS to display one character from the ...
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1answer
689 views

RL circuit: How to determine the equivalent resistance of the circuit?

So I'm working on an RL circuit and the solution is stated to be that R1 and R3 are in series, but I didn't think that was the case because they don't have the same current through them. Given ...
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2answers
238 views

Activating a circuit based on change of resistance

I am looking to use a sensor, such as photoresistor, to activate a circuit only when there is a significant change in the input. Such as when the light incident on the photoresistor changes ...
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3answers
487 views

Are Civilian GPS signals cryptographically signed?

As far as I understand, receiving enough GPS signals at the same time enables to deduce the position and the time. So I guess it is possible to use an offline receiver as a very precise clock? If so,...
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1answer
340 views

How is rise/fall time definition

I understand that rise/fall time are related to RC charging/discharging waveforms. What I don't understand is how is the 0% and 100% points chosen? Do they have to be defined beforehand for a signal?...
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987 views

NPN transistor slow to turn off even when operated outside of saturation region

I am currently studying how transistors react and behave to simple signals. I have the following circuit: A square wave of approximately 83kHz is applied. The transistor used is a 2N5551. The ...
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1answer
118 views

Does the Epson RX8900 real time clock count the year “00” as a leap year?

The datasheets ambiguously say... A leap year is set whenever the year value is a multiple of four (such as 04, 08, 12, 88, 92, or 96). Is zero a multiple of four? This is more of a philosophical ...
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1answer
209 views

IEEE 1588 PTP phase and time synchronization

Why everywhere is said that PTP synchronize phase and time together? phase and time are totally separate concepts. does it mean after using PTP rising edge of slave and master clocks happen ...
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1answer
1k views

Voltage time graph integration

In a Voltage time graph , at constant current I= 170 amps, voltage=0 to 5,5 and time= 0 to 97 sec and voltage decreases from 5,5 at 0sec to 1,16 at 97 sec, now how can I find the total power ...
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2answers
777 views

Change a quartz clock timebase by changing the frequency of the quartz crystal oscillator?

I've been doing some research on rewiring clock circuits for a project, but I'm new to these types of pulse-counting circuits. My question at this point is: If I replace the existing quartz crystal ...
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2answers
254 views

PIC period measurement sometimes 1 overflow count wrong

Short info: I'm using a PIC18F4580 to measure the period time of two positive pulses using the CCP 1 on the MCU. And then writing the result to an LCD. When testing I sometimes get a result thats one ...
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1answer
78 views

Confusion about power in an RC circuit

Funny this is my third question in a row about RC circuits, but I wanted to figure out some stuff I'd been wondering for a while. What I was confused about the power while charging. Like say that ...
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2answers
147 views

Is it possible to speed up Battery simulations with power converters in Simulink?

I am facing a huge problem with real-time analysis of a PCS simulation. I want to simulate a power converter system, which can be used as a power converter. I have to do an accelerated simulation with ...
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Can someone please help me with this pipelining question

A pipelined implementation of the circuit shown below is to be designed. The delays of the building blocks are indicated inside circles. You are given buffers with a delay of 0.5 ns, and flip-flops ...