Frequency counter alert sound - Electronic Circuits Projects Diagrams Free

BTDe · 27th February 2006, 09:24 PM

HI WORLD,

actually i am building a Frequency counter, i did almost finish it, now i want a sound system to be added to it,. the fuction of it will be to indicate when a certain frequency is reached but i do not know which kind of circuit and how to connect to it. well i want the sound to be operated to ialert the user when the frequecy = 84Hz or above is reached.
it will be even more exciting if this frequicy at which the sound is operted is varied that is if you could set a freq. and at that frequency or above the sound is operted, but that will require more complicated circuit, which i will do later but if it is also easy then may be i'll do it now. what do you think.
can any one help

P.S. i am new to this field so please help from the basics. :?:

Russlk · 27th February 2006, 10:17 PM

Sounding a beep on 84 count is easy, just decode 1010100, but if you want to sound the beep on any count over 84, then you need a frequency to voltage circuit (LM2907) and a comparator.

JimB · 28th February 2006, 12:05 AM

Too many unknowns.

How does the frequency counter work?
Is the count available in binary or BCD?
How accurate do you need the alarm?
Where is the 84hz coming from?

Making a whole lot of assumptions of my own, I think the easiest solution would be as proposed by Russlk:

Use a frequency to voltage converter to give a voltage which is proportional to the frequency.
Compare the voltage with an adjustable reference voltage using a comparator.
Use the output of the comparator to drive your audible alarm.

You then have something where the alarm point is easily adjustable.

The idea of doing the alarm from the counter sounds a really bad idea for a beginner.

JimB

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27th February 2006, 09:24 PM	(permalink)
BTDe	Frequency counter alert sound HI WORLD, actually i am building a Frequency counter, i did almost finish it, now i want a sound system to be added to it,. the fuction of it will be to indicate when a certain frequency is reached but i do not know which kind of circuit and how to connect to it. well i want the sound to be operated to ialert the user when the frequecy = 84Hz or above is reached. it will be even more exciting if this frequicy at which the sound is operted is varied that is if you could set a freq. and at that frequency or above the sound is operted, but that will require more complicated circuit, which i will do later but if it is also easy then may be i'll do it now. what do you think. can any one help P.S. i am new to this field so please help from the basics. :?: __________________ BLUE BTDe of NIMCOP nakhanw@essex.ac.uk bluenavz@yahoo.com ONCE KNOW THYSELF

27th February 2006, 10:17 PM	(permalink)
Russlk	Sounding a beep on 84 count is easy, just decode 1010100, but if you want to sound the beep on any count over 84, then you need a frequency to voltage circuit (LM2907) and a comparator. __________________ see my website: www.geocities.com/russlk

28th February 2006, 12:05 AM	(permalink)
JimB	Too many unknowns. How does the frequency counter work? Is the count available in binary or BCD? How accurate do you need the alarm? Where is the 84hz coming from? Making a whole lot of assumptions of my own, I think the easiest solution would be as proposed by Russlk: Use a frequency to voltage converter to give a voltage which is proportional to the frequency. Compare the voltage with an adjustable reference voltage using a comparator. Use the output of the comparator to drive your audible alarm. You then have something where the alarm point is easily adjustable. The idea of doing the alarm from the counter sounds a really bad idea for a beginner. JimB __________________ Experience is directly proportional to the value of the equipment ruined.