Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [frequency-measurement]

Anything related to the measurement of the frequency of periodic signals, i.e. the rate at which their waveform repeats along the time axis. The S.I. unit for frequency is **hertz [Hz]**.

Anything related to the measurement of the frequency of periodic signals, i.e. the rate at which their waveform repeats along the time axis. The S.I. unit for frequency is hertz [Hz] and it is equivalent to \$ [s^{-1}] \$ since it represents how many times in a second the waveform repeats itself.

See also Wikipedia on the meaning of frequency.

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Oscilloscope Bandwidth, what's it all about?

This question popped up to me a few moments ago. I was measuring what is intended to be a 50Mhz square wave of level 0 to 2.5, however what I saw on the screen is a sine wave that was centered around 1.2V and level of 0.5 to 2.0V, the frequency was…
Kevin Boyd
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How to measure pulse width of an IR signal using an 8-bit PIC?

My friend and I want to design a universal learning remote controller, like this one, for learning purposes. What we want to do basically is store and replay infrared pulses. We want to detect 36kHz, 38kHz and 40kHz signals. A 40kHz signal will have…
abdullah kahraman
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How to test a crystal resonator in board?

I have 2 quartz crystal resonators in my pcb board: 32.768 kHz & 20 MHz. They are connected to a Freescale MC12311 transceiver IC, which has an HCS08 micro-controller embedded in it. I want to test if these crystals are working properly or…
Omid1989
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Measuring frequency of a signal above 5V with a microcontroller

I want to measure the frequency (up to 300 Hz) of a rectangle signal, that varies between 0V and Vtop, where Vtop is anything between 5V and 15V. Because I cannot apply more than 5V to the microcontroller (PIC16F1827), I need to limit the voltage…
PetPaulsen
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How are high-speed circuits tested if test equipment doesnt exist?

How was testing done for Ghz to THz range circuits and devices before fast enough scopes and frequency counters existed?
FourierFlux
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Measuring 0 - 1MHz ( 0.25Hz resolution) Squarewave using an MCU

I need to measure the frequency of square-wave that can vary between 0 and 1MHz, and has a resolution of 0.25Hz. I havent decided on which controller yet but It will most likely be one of the 20pin Attiny's. Normally how I would measure lower…
volting
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3dB Cutoff Measurement vs (Calculated + Simulated)

I am stumbling upon a very strange situation unless I did something totally wrong in my measurement setup. Speaking of it, I've installed an acoustic measurement tool (REW) and measured for testing purposes an RC lowpass filter by using two mono…
abg1984
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Why is 30MHz Clock signal distorted on oscilloscope?

I'm trying to probe a 30MHz clock signal, coming from an FPGA and routed to a CCD sensor. There are no other components, other than connectors, between source/destination. When I probe this signal with my oscilloscope, I get a distorted waveform…
Xander
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How can I track where this 471kHz noise is coming from?

I'm new to EE in general and I just received my first oscilloscope (Rigol DS1102E). Anyway, I'm building an audio circuit using an Arduino Micro and the infamous SN76489 (info) OK, so basically I have 8 digital pins from the Arduino tied to the…
cbmeeks
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Capturing mains AC waveform with audio recording device

I'm wondering how practical (read: safe) it would be to use an audio capture device to "record" a mains AC signal for the purposes of monitoring the characteristics of the AC sine wave. I am thinking something relatively simple like a feeding the…
Malvineous
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Direct frequency measurement with two hw timers

In what modes would I set two timers to directly measure frequency on an STM32F303 microcontroller? Right now I set up one timer in ETR mode and gate it with systick software interrupts, but I would like to have a second timer gate it directly to…
Tomas Svitil
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How to measure self resonance frequency of coil using CRO?

I have antenna coil for tuning an antenna. I want to measure self resonant frequency of the antenna coil. Can anyone tell me how to measure it with an oscilloscope? What will be the experimental setup?
Electroholic
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Why does my crystal oscillator spike so much?

I just got a new oscilloscope (Rigol DS1102E) and I'm new to EE in general. One of the first things I put on the scope was my 3.579Mhz "TKD" crystal oscillator. What I didn't expect was the spike on each rising and falling edge (hope I said that…
cbmeeks
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High pitch audio frequency measuring

Wondering on how could higher pitches than 23 kHz be measured, I can only find devices measuring to about 21kHz. Main question is: how could audio frequencies about 26 kHz or 30 kHz be measured, on dBFS and frequency; ones on my smartphones,…
Waldemar22
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How to correctly simulate a simple LM2907 circuit in LTSpice?

I'm trying to convert the frequency of a 0-5V square wave, which ranges from 0-20kHz, to a voltage using a simple LM2907 (8 pin) circuit. Using R1 as 100k, I've calculated C1 to be 416pF for a maximum output of 12V @ 20kHz. However, when I do a…
Petrus Theron
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