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555 beep in bursts

I'm trying make a non microcontroller circuit that gives about 5 quick beeps then roughly 1 second off, repeat. I'm running on 2 AAA batteries. I already have a bunch of cmos 555 on hand so was trying to make that work. I'm using a 3V active buzzer which is quite loud. I tried a few astable variations, the attached circuit with R1=1K (in series with variable resistor), R2=100K, C=10uF gave me the desired timing sequence but doesn't beep, just a steady on, 1 second off, repeat. What changes can I make to get the desired timing but with beeps.
Thanks,
Rich.
 

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If at a later time you get around to trying mBlock here
I modified adding variables to set to easily change burst
parameters.

1711208462097.png



Regards, Dana.

PS : By the way here is a talking voltmeter done with a different block language. Once
you learn one its easy to do other variants on the block languages. I used this to adjust
a design while across the room from the design, eg. adjusting box while using PC to
measure with test equipment box parameters. Think test equipment remote slave.

 
Interestingly one of the earlier posts declared it impossible
That was me and yet I was the one that made it possible to use uno CMOS 555.
  • In #1 you had a design flaw but insufficient details to analyze and unclear specs for timing.
  • In #3 I offered specs: 0.1s On, 1 sec off, for 5 cycles and stop.
  • In #4 you replied agreeing to 5 quick bursts
  • After I realized you were not fussy about how quick or long the bursts were I compromized the #3 specs with the 3 timer solution by choosing long ~ 50% pulses to use the square wave astable repeated 5 times in one. Doing #3 as I suggested would add more parts. eTech also had a model working to his understanding with a 555 and suggested a good alternative solution using Schmitt NAND and low Vgs FET(redundant for 1k load) in #8
For other students/engineers/hobbyists reading please try to be as precise in your problem statement in #1 with :
  1. Purpose
  2. Measurable specs and functions
  3. Tolerances ( must /may haves and/or %)
  4. other relevant inputs and outputs
You're welcome.

Those suggesting a < $1 uC solution are not wrong for them but not right for you.
 
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This is a quick demo of the CD4060 circuit I described a few pages back;

it needs the IC, around six resistors, a couple of caps, a transistor and three or four diodes to switch power to buzzer or speaker. There are extra couple of bits on the breadboard to allow it to switch the transistor and an LED at the same time.

 
In case Piezo not loud enough at low battery V remember a bridge drive approach of it
which yields up to 4X the power of a single ended drive, due to voltage doubling :

1711289754023.png


Due to P = E^2 / R

Caution, Piezo's have a limit of Vdrive before mechanical fracture, so specs matter.

Also : https://electronics.stackexchange.c...de-in-this-driver-connected-to-a-piezo-buzzer

Lastly note you rarely ever get 4X because driving sources not true V sources, their
loads compromise swing.


Regards, Dana.
 
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I think the easiest and most obvious solution is as follows...
In case Piezo not loud enough remember do a bridge drive of it which yields
up to 4X the power of a single ended drive, due to voltage doubling :

View attachment 145101

Due to P = E^2 / R

Caution, Piezo's have a limit of Vdrive before mechanical fracture, so specs matter.

Also : https://electronics.stackexchange.c...de-in-this-driver-connected-to-a-piezo-buzzer


Regards, Dana.
he doesn't have a simple piezo - he has a buzzer module that works on 3v DC
 
This is a quick demo of the CD4060 circuit I described a few pages back;

Love me some 4060, but like the 4093 it's operation below 3.0 V is undefined.

About the circuit - given that the oscillator freq is adjustable, I don't think you need full decoding of the 4060 outputs to get a wide operating range. IOW, I think you can delete 6 diodes and three resistors. Because of the low operating voltage, I would go with a Shottkey diode, and a bipolar driver transistor for the beeper. Schematic to follow.

Also, the variable resistor goes to pin 10, and a much larger resistor goes to pin 11.

ak
 
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I think the easiest and most obvious solution is as follows...

he doesn't have a simple piezo - he has a buzzer module that works on 3v DC

All the more reason to consider, if design sound level not great enough, especially
considering its a 3V design, to consider the bare Piezo.....but he is also space limited,
although you can get tiny logic buffer parts in very small packages to aid in this
approach.



Regards, Dana.
 
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Then there's that other solution thats good down to 1.8V, but thats for another day per OPs wishes.

Of course thats a whole other challenge to repeatable sound volume....


Regards, Dana.
 
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Here is a version of the circuit based on a CD4060. It has the same operating voltage issue as the CD4093 circuit, but other that that it is pretty tight.

I went with a bipolar driver transistor to get the max voltage across the beeper. A 2N7000 FET might work, but again there is that whole low voltage thing. If you go with a FET, R4 can be increased 10x.

ak
Gated-Beeper-4-c.gif
 
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The circuit in #14 looks like it pulsating beeps for about 6 seconds, then goes completely off. Is that correct?

ak

This is a quick demo of the CD4060 circuit I described a few pages back;

it needs the IC, around six resistors, a couple of caps, a transistor and three or four diodes to switch power to buzzer or speaker. There are extra couple of bits on the breadboard to allow it to switch the transistor and an LED at the same time.

Good show there rjenkinsgb. I'll definitely bear that chip in mind for future projects. For now I want fewer components and to hopefully still be functioning when that 3v inevitably dips to around 2.6V. I should have those parts in a day or so. Closer to the 8 beep than the four would suit me. Appreciated.
 
R3 in my T3 timer controls the # of beeps.
 
Did you ever accept answer for the fewest parts?

TL;DR

 
Did you ever accept answer for the fewest parts?

TL;DR

I have to tell you life takes funny turns. Fedex after my 1 week wait, left my digikey package on the mailroom floor instead of delivering it to door. Somewhere out there is a less than pleased criminal with all my ICs, or maybe my contribution to the start of someone's electronic career. I was so annoyed I opened my IDE and ended up writing a code for the Attiny85 (Somewhere out there Danadak is having a good laugh) which works well. I have since reordered and received those chips and I'll be testing in the next few days and will definitely report back. Thanks.
 

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