# What are the methods of measuring frequency?

1. ## Measuring Frequency

I want to know the all method of measuring frequency?Who can help me?

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2. ## Re: Measuring Frequency

Hi
The one which i like is the zero-crossings method...
Just implement a zero-crossing comparator with a 1 second counter... and you have the frequency..

3. ## Re: Measuring Frequency

Originally Posted by xischaune
Hi
The one which i like is the zero-crossings method...
Just implement a zero-crossing comparator with a 1 second counter... and you have the frequency..
You don't even need a comparator if d input is Square wave , just feed it to clock of counter which will count pulses and output dvided by time taken to reach there will give u frequency.

Alternatively circuits r there that convert frequency to voltage : use analog version for sin input and digital for square wave input

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4. ## Re: Measuring Frequency

What is frequency of a signal? It is number of periods in a second.
Count periods in a specific time and calculate frequency.
Period of a signal is inverselly proportional to it's frequency. Measure duration of a period and calculate frequency.

What previously posters said is dealing with signal conditioning before measurement and is not a method of frequency measurement.

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5. ## Re: Measuring Frequency

Originally Posted by Borber
What is frequency of a signal? It is number of periods in a second.
Count periods in a specific time and calculate frequency.
Period of a signal is inverselly proportional to it's frequency. Measure duration of a period and calculate frequency.

What previously posters said is dealing with signal conditioning before measurement and is not a method of frequency measurement.
Provided you hv a CRO

6. ## Re: Measuring Frequency

CRO is one of possibillities. Sometimes you may use allso a seconds pointer on your watch. At some other indirect methods the use of a voltmeter or a meter or a scales is possible. But you always must count a number of periods or length of it.

7. ## Measuring Frequency

You could consider a frequency to coltage converter and caliberate the voltgae to know the frequency.

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8. ## Re: Measuring Frequency

First bring down the voltage to 0-5 volts range using conventional voltage divider. Then feed this signal to a schmitt trigger based on an opamp. Then give this signal to CCP input of PIC 16f877 microcontroller. Search the michrochip website for an application note and u surely will find one.

9. ## Re: Measuring Frequency

Internet is full of frequency counter projects, mostly based on PIC MCU.

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