Solution for a DC buzzer which will give out 2 different tones

[Jayakarthick]

Hi all.... Thnx all for keeping this forum so lively....I require a feedback from u all for my design to go ahead in my project. In my application

I use a DSP processor(OMAP) to do some signal processing algorithm.

If I encounter a critical condition I should turn on the alarm/buzzer.... actually there are 2 different critical conditions so two tone is essential...

I am planning to use a simple DC buzzer.... From GPIO pin of DSP to control switch of the buzzer.... Now is it possible to get two tones in this case? Or should i use PWM module in DSP to control the switch at various intervals so that i get two different tone? plz suggest some simple solution....Since it is handheld device In my later design is it possible for me to give an user option to hear the sound in ear phones?? how to design that?

Thanks in advance....

 

[Jayakarthick]

Re: Buzzer Clarification

Hi is there anything wrong in the question? am I posting in the wrong place of the forum...?? I am new to this forum....

 

[pranam77]

Re: Buzzer Clarification

Hi is there anything wrong in the question? am I posting in the wrong place of the forum...??

You cannot change the "Tone of a buzzer unless you modify its oscillator. All you can do is switch the buzzer at different intervals. Mean one sec on and one sec off for one situation and may be .5 sec on and 2 sec off and so on for other requirements...

I am new to this forum....

You have joined the forum on 18 Nov 2009. So its nearly 4 months now and you are not new to the forum. You are a newbie with just 8 posts till date.
Cheers

 

[nandhu015]

Buzzer Clarification

Another choice is you can use a small speaker and generate different frequencies in the processor itself

Nandhu

 

[Jayakarthick]

Re: Buzzer Clarification

Thanks a lot pranam and nandu....

Both the solution looks feasible but I need to get the buzzing sound in head phones also... I need an amplifier/driver circuit for that in both above mentioned solution? any circuitry?


@Pranam
Yes I registered long back but couldnt visit often since I am DSP programmer that is why I meant new to the forum....


Regards
JK

 

[nandhu015]

Buzzer Clarification

The output from processor needs a bit amplification. A simple transistor amplifier is enough

Nandhu

 

[pranam77]

Buzzer Clarification

You may also consider a tone generator built arround 555 timer which can be used directly with the head phones / earphones without further amplification...
Cheers