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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]**.

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2answers
67 views

Non-intrusive measurement of current and voltage

Sorry if this question is too basic for this forum... I'm an interested amateur but far from a professional. I'd really appreciate information from someone more informed than myself. Hypothetical ...
0
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4answers
79 views

Frequency Ratio Circuit

I'm attempting to design a circuit that will determine the frequency ratio between a known reference frequency \$f_\text{ref}\$, and an unknown signal frequency \$f_\text{sig}\$. The signal frequency ...
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1answer
73 views

Methods of measuring speed of anemometer

I enjoy DIY, but to keep things simple I purchased an anemometer cupset (3 cups). I feel that a magnetic reed switch would get "bounce" at higher speeds and I was thinking of a disk with a slot, and ...
0
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1answer
78 views

Maximum switching frequency

Is it possible to calculate maximum switching frequency of IGBT having only datasheet in hands? https://www.semikron.com/dl/service-support/downloads/download/semikron-datasheet-skm200gal173d-...
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0answers
78 views

Rubidium standard mystery output?

I've been playing with a frequency counter (Racal 2202R) that has a built-in rubidium standard. It has two outputs, "Rb OUT 1" and "Rb OUT 2". I could not find any documentation at all, but the ...
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1answer
45 views

Unit conversion: dBμV to dBm, including measured frequency

I'd like to ask for help with conversion of measured voltage V=10dBμV to dBm units. Voltage is measured on frequency ...
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3answers
366 views

Is it possible to measure frequency upto 500Mhz with 50Mhz oscilloscope?

Is there a way to measure higher frequency measurements with a 50 MHz oscilloscope (eg rigol ds1054z)? Perhaps some post processing of captured waveforms? Or with the help of some adapters? I have a ...
0
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3answers
138 views

Measure frequencies fast and precise

I need to measure frequencies between 25kHz and 150kHz with a precision of minimum 50Hz. I'm using a MCU 8051(C8051F382 Silicon) with 48MHz clock, and need the measure to be done under 100us, so I can'...
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2answers
58 views

Circuit for converting motor tacho-sensor sine wave output to 5V TTL for MCU

I'm trying to measure the speed of a washing machine motor. The motor has a speedometer attached to it, which generates a sine wave with frequency equal to rotation frequency of the motor. I'm ...
0
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2answers
55 views

What are the methods to measure distribution transformer vibration in 0.5g range?

It may seem obvious to use widely available analog devices MEME accelerometer for measurement in range of 0.5g. I did thorough study on this and found out that MEMS sensors either doesn't work or ...
0
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1answer
78 views

Can the frequency of an electrical current be heard and distinguished from other frequencies just by connecting circuit to a speaker?

I have a circuit that I want to be able to detect the frequency of the current going on it (part of the circuit is AC, the power supply is going to be at least 3v, probably 5v, and 6v DC at most). I ...
2
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2answers
109 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 ...
2
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5answers
401 views

Reciprocal Frequency Counter Mean

I have designed a high precision frequency counter circuit. I am using it to measure a frequency of around 35kHz that is stable to 0.1mHz. I can measure the frequency using a Stanford Research Systems ...
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1answer
66 views

Frequency Counter Problem

I'm a Electrical Engineering Student and i have to respond to this question before I can do the lab work. "A frequency counter with an internal 1MHz oscillator and six frequency dividers is given to ...
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0answers
34 views

Why the result of stepped-frequency continuous radar result does not match with the outcomes found in literature?

I have a confusion about frequency modulated signal based radars as follow; In literature two-way delay related to the target is defined as; $$ \tau(t) = \frac{2R}{c} $$ and transmitting signal is ...
0
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1answer
127 views

Enabling external reference to HP/Agilent Signal Generator (8648C)

What is the proper way to use an external 10 MHz clock signal for an HP/Agilent signal generator (in my case: 8648C)? With my Tektronix, Rohde & Schwarz devices, internal/external reference has ...
1
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2answers
784 views

LTSpice: How to use .meas command to find the fundamental frequency of non-sinusoidal signal?

I want to find fundamental frequency of a periodic signal (non-sinusoidal) in certain time window using the .meas command in LTSpice. I was using the following ...
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0answers
20 views

coaxial lightning surge protection

I am considering something like a CHSPCABLE or a "TII 212 Broadband Cable TV and Satellite Lightning Surge Protector 75 Ohm 5-1500MHz" I have xfinity, I inquired about the compatibility of a chspcable,...
0
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1answer
239 views

Simple way of measuring RPM of motor by How to make Frequency/Pulse counting circuit

I want to measure RPM of a motor. For this, I am planning to put an assembly where an IR LED facing with IR sensor under line of sight. With every rotation, the line will be cut once - and hence the ...
1
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1answer
66 views

Grounding oscilloscope probe effects

I have built an active band-pass filter on a breadboard with the use of an MC33078p op amp. Gain is 32 on paper. When I apply the AC signal to the circuit, 18.1mV P-P and 660kHz, the oscilloscope ...
3
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4answers
328 views

Differential Amplifier's Unusual Behavior

This circuit is made of one differential BJT transistor pair and voltage-amplification stage with negative feedback. simulate this circuit – Schematic created using CircuitLab About this ...
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3answers
153 views

Is a 0.01s time base really useful in a frequency counter?

I am currently designing a frequency counter based on the PIC16F628A. It is working as expected but I would like to add some useful features. According to the images found by googling, I noticed that ...
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1answer
107 views

Measure duration of a non periodic message on FPGA with VHDL

I'm trying to measure the duration of a non periodic signal(message) on FPGA, as below : I want to measure the duration of the measured signal by counting the number of reference clock's period. I ...
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0answers
321 views

interfacing tcs3200 color sensor with STM32f746zg

I want to interface TCS3200 color sensor with STM32f746ZG. Since the TCS3200 outputs a frequency based on the amount of light received, I need some way to count the number of pulses for different ...
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4answers
273 views

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?
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3answers
191 views

Count based frequency meter

I'd like to understand how a frequency meter treats a sine wave, i think i got it, but still I'd like some confirmation. So i was taught with square signals where the meter counts the impulses in a ...
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1answer
85 views

What's the difference between measurement resolution and digits per second in time measurement devices

In time/frequency counters/analyzers in technical specifications you can almost always find resolution and digits per second values next to each other. What is the difference?
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2answers
446 views

sampling rate and frequency response of a vibration sensor

I am trying to measure the vibrations of a lathe machine using a piezoelectric accelerometer sensor. I want to know if the sampling rate can be set at a value greater than the flat response frequency ...
0
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1answer
338 views

how to measure phase response of filter

I have a lowpass filter (0 - 2MHz). I wanted to measure the phase response but I am a little bit confused. I have a signal generator and oscilloscope. Any tips how I could accomplish that? Edit: ...
0
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1answer
82 views

How can i convert an AC output from an outlet to a digital signal? [closed]

I´m making a digital frequency meter and want to compare the frequency from an outlet with a stable 1hz frequency from a crystal using an AND logic gate. However, I´m not sure how can i get a digital ...
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2answers
172 views

incorrect i2c frequency?

I am using an ATTiny88 MCU as master over an Si4012 slave. The MCU is running code produced by Arduino IDE. Connecting a logic analyzer to the SCL and SDA lines produce an output as below - second ...
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1answer
142 views

How to measure frequency of AC Voltage(In range of 0.05-5v) using micro-controller?

I have one sensor which outputs in the range of 0-5v AC voltage and I want to measure a frequency of this signal using the microcontroller ? Is there any IC which gives digital pulse in output when ...
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1answer
152 views

Trying to understand how to design the gate of a frequency counter

I´m trying to design a frequency counter for my physics class. My teacher demanded that we build it using a 32768 Hz crystal and 4060 ic. In my research i stumbled across this design: I don´t have a ...
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1answer
593 views

Digital Multimeter not working on higher frequency

I have an ordinary multi-meter which looks like the one below in the description. When i measure higher frequencies above 200kHZ the voltage is not showing up properly as it says on the frequency ...
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2answers
2k views

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 ...
2
votes
1answer
163 views

an/prm-10 grid dip question - how the voltage can be negative at the grid? [duplicate]

I am trying to repair a recently bought AN/PRM-10 grid dip. I have replaced some electron tubes by new ones and (almost?) everything seems to be OK regarding the voltages at the pins of the electron ...
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1answer
315 views

Designing a senvitive frequency to voltage converter

I need to make a battery powered frequency to voltage converter that will monitor very minor frequency changes, around 100Hz with base frequency of 3-5MHz (may vary during operation); something like a ...
2
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0answers
403 views

Crystal Oscillator Design and “Crystal Drive Level”

I followed the video at the link http://www.analogzoo.com/2015/07/ . The video directs watchers to a tool at http://www.analogzoo.com/lab/pierce_bjt.html to help determine parameters to cause ...
2
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3answers
109 views

1-11 Hz to DC voltage signal

I'm doing an internship where we are connecting all kind of sensors on a CAN-network for an automated datagathering. There is one sensor that sends a 50% duty cycle frequency signal between 1 and 11 ...
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4answers
1k views

Does a BNC splitter introduce defects into the signal?

I'm currently doing some contract work that includes finding and recommending a signal generator model for frequency measurement device verification. The verification scheme requires generating a ...
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4answers
137 views

Overtones Produced From Speaker Load on Asymmetric Square Wave

What I am doing I built a circuit using a 555 timing chip in astable mode which produces a square wave. There is a potentiometer which allows me to adjust the frequency produced. One aspect of this ...
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1answer
382 views

Photo diode TIA

here i have designed a TIA circuit with the suitable values for the feedback resistance and feedback capacitance and using the FDS100, to achieve a bandwidth around 43 MHz, the simulation is running ...
0
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1answer
139 views

NE555P Frequency Drop to 0 after a couple of minutes? [closed]

I'm trying to build a frequency measurement circuit using NE555P and Atmega328P. The circuit is the following : I use this library https://www.pjrc.com/teensy/td_libs_FreqCount.html Always, The ...
2
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1answer
202 views

How do I calculate limit frequency of the attenuator circuit?

Calculate the limit frequency \$fg\$ of the attenuation \$v_u =\frac{ u_a} { u_e}\$ at the current source I (for the value given in example), so that for \$f>> fg\$ exist ideal behavior. Note: ...
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1answer
95 views

Could a lower bandwidth or rise time oscilloscope be used for measuring a stable phase shift between two channels?

I’m trying to design an experimental setup to measure the speed of EM waves transmitted from a small solenoid antenna (It won’t transmit effectively but I have to make the antennas more “point like”) ...
2
votes
3answers
768 views

FFT Using Pic Microcontroller [closed]

Good Evening, I am fairly unfamiliar with DSP and want to engage in a project. I wish to perform a FFT on the source current going into a non-linear load and observe its harmonic content on an LCD. ...
0
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1answer
141 views

Sampling and Aliasing Problem

I have this problem where I was able to solve for both a and b but I am stuck on c and d. For part a I came up with 0 Hz, 4.77 Hz...
0
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2answers
398 views

frequency meter using Adafruit Feather M0

I want to measure the frequency of the pwm signal I will be receiving at a certain I/O pin. The issue is, I could not find any library or code written for this board. I could find this library for ...
0
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2answers
80 views

Maximum frequency measured by STM32F10x

I've gotten a question about STM32F10x frequency measurement. 1. what is the maximum frequency which can be measured by this micro and its timers especially the advanced timers. 2. what are the limits ...
0
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1answer
374 views

Counting signal frequency with binary counter

I'm trying to count the frequency of an audio signal using a 393 binary counter which is read by an Arduino without using its ADC. If the reading is done once per second, should the counter be somehow ...