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Simple Timed Beep Circuit

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Scalamoosh

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I came across a circuit online which nearly does what I am wanting. I was just wondering what would be needed to enhance it a bit.

adjustable-timer.gif

The above circuit (when switched on) will light up the green LED, and once the timer has finished (controlled by the variable resistor) will sound the speaker and light up the green LED.

What I am wanting:
- The switch to be a push-to-make switch that starts the timer
- Once the timer finishes, I want the speaker/buzzer to beep a few times then the circuit to turn itself off

I haven't built the above circuit yet, so any re-designs of the circuit are possible.

Thanks in advance.
 

Your outputs could be clarified or a purpose given.

Can you add info e.g. V,t(sec.),f (Hz) on a timing diagram?

In ___-______________________
Out_____________---------_____
Out2_____________-_-_-_________
 

Hi, sorry for the rushed (and not very helpful) opening post.

I want to create a simple circuit where I can press a button (enabling the device) which will then notify me (via alarm, and LED) once the timer finishes. With the above circuit, I believe i can alter the devices time from roughly 1-10 mins using the variable resistor. (This is the sort of times I am looking for)

The actual output of the beeps isn't all that important. Either a few short beeps or one longer beep for a couple of seconds. (what I don't want is the device to keep beeping until somebody switches it off)

The voltage to be used is a single 9v battery.

Does this give you enough information?

I'll be honest, I'm not sure what you mean by a timing diagram, but I'm hoping the above information is enough?

Thanks,
 

An ordinary 555 timer uses a fair amount of battery current when it is timing. A Cmos 555 (LMC555, TLC555 or ICM7555) uses almost no battery current when it is timing.
One timer IC can be the timer and a second timer IC can time the beep for a couple of seconds.

A dual 555 is a 556 but I do not know if a Cmos 556 is available.
 

The reason I was using standard 555 timers is because I have a bunch of them going spare. I know they are dirt cheap but I would rather use the ones I've got than by more.

Im just looking for a good schematic of how to build it as my knowledge of 555's is pretty non-existent.

Cheers,
 

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