Low power buzzer ideas

[orcaja]

Hi there!

I would like to make a small, low power buzzer. I was thinking about using a crystal to get the sound. I want to make an intermitent buzzer, every beep will be around 100ms, and it will be working every 1.3 seconds. I want to do something similar to a "Tempo Trainer MR" for swimming, but simpler.
:lol:
Any ideas?
Joc

 

[Genovator]

One thing you can do is use a dual timer IC, NE556 or two pieces of NE555 to produce two different frequencies. One timer will produce a frequency of 0.714 Hz with duty cycle of 7.14% for the 100ms beep and 1.3s delay.
Another timer will produce a frequency range of around 800Hz to 2000Hz or more (adjustable) to create noise for the buzzer.

Control the second timer with the first one and you will get exactly what you need. These IC's are cheap and requires few passive components.

 

[orcaja]

One thing you can do is use a dual timer IC, NE556 or two pieces of NE555 to produce two different frequencies. One timer will produce a frequency of 0.714 Hz with duty cycle of 7.14% for the 100ms beep and 1.3s delay.
Another timer will produce a frequency range of around 800Hz to 2000Hz or more (adjustable) to create noise for the buzzer.

Control the second timer with the first one and you will get exactly what you need. These IC's are cheap and requires few passive components.

Thanks for the idea.
I was looking at the "minitracker" **broken link removed** and I was thinking about using the first two transistors to get a pulse of 100ms every 1.5 seconds. I thought that I could use that to enable an oscillator of around 4kHz and a piezoelectric buzzer. The idea of the 555 or 556, sounds good, but according to the datasheets, the minimum voltage is 4.5V, I was thinking about using 3V. I was wondering how does the buzzer in a wrist watch work?, it seems that they are low power, and the battery should last for a long time.

Any other ideas?

 

[BradtheRad]

I built a similar beeper from the oscillator that can be made from two logic inverters, a resistor, and capacitor.

The inverter IC can be 4049 or 4069. Six inverters are on one chip. I forget whether they work on 3V.

I used two oscillators, (a) one at high frequency, (b) the other low.

The high F one drives a piezo beeper.

The low F oscillator is the on-off device. Its output alternately allows and prevents operation of the second oscillator.

To do this, the output of the first oscillator goes through a diode and resistor, to the next oscillator (the high F).

 

[Genovator]

You can use ICM7555 or TLC551 for low voltage timing. The idea given by me and BradtheRad are more or less same and it will be easy for you. You have to use two oscillations to drive the buzzer....