# Counting The Number of Clock Pulses in the Period of the Waveform

#### VEDELAGO!!

Joined May 8, 2007
6
Hello Everyone,

For my homework, i have been given the task of designing a circuit which counts the number of clock pulses in the period of waveform A (attached image).

I have done a couple of hours of research and have come across something called a frequency counter.

Will using a frequency counter (which i believe involves the use of J-K Flip-flops) actually count the number of clock pulses in the period of waveform A?

- VEDELAGO!!

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#### beenthere

Joined Apr 20, 2004
15,819
Freq counters use an accurate time base to count the input pulses for a period of time. The period is fixed, so the frequency scales directrly to frequency. With a front end conditioning the pulses to a compatible logic level, any logic family counter chip may be used - not just J-K FF's.

#### VEDELAGO!!

Joined May 8, 2007
6

I'm just not sure on the part where you say
Freq counters use an accurate time base to count the input pulses for a period of time. The period is fixed, so the frequency scales directrly to frequency
Do you mean that frequency counters need to use the original clock pulse to count the input pulses?

If you could elaborate a little it would be much appreciated

Thanks.

- VEDELAGO!!

#### recca02

Joined Apr 2, 2007
1,214
one idea that i get is:
i think u can use the clk pulse to drive a counter.
if u want a pulses per second display may be use of a timer ckt (monostable or bistable)
which disables the clk i/p after one sec might work.

#### beenthere

Joined Apr 20, 2004
15,819
Imagine a counter that is enabled to count pulses for a period of one second. The accumulated count would be the number of pulses in one second, which, times 60, is the pulses per minute, or the frequency.