Geiger counter click sound simulator circuit

[4pyros]

I am going to make a prop for a haunted Hayride. It will be a Geiger counter with a simulated varible click sound.
A working Geiger counter with headphone output has been ordered.
We want to use it without any radiation and add a speaker so the sound can be heard without the head phones. Need to make the clicks go faster and slower just like the real thing.

I am thinking I can use a 555 timer and drive a speaker directly, but what timing arrangement do I need to get realistic click sounds?

Any thoughts?

Andy

 

[ccurtis]

A working Geiger counter with headphone output has been ordered.

Why? Just in case the hay ride really might be haunted?

 

[ronv]

It's kind of a random sound - I'm trying to think of a way. Do you want to control the speed of it by hand?

 

[ronv]

Maybe one of these followed by a low pass filter fed to a 555 for a speaker pulse?

https://secondhandsynth.wordpress.com/2010/04/08/random-white-noise-sample-and-hold-circuit-part-1/

The little love dumpling says try Toys R Us.

 

[crutschow]

Here's a discussion of a fake Geiger circuit which uses a short μP program to generate the random sound.

 

[alec_t]

Something like this?
View attachment 66236

 

[4pyros]

Why? Just in case the hay ride really might be haunted?

We need to get the patron's off the wagon for a walk thru part of the hay ride.
Thay just went thru a toxic scene and we are going to tell them they are radio active and need to get off the wagon.

 

[4pyros]

It's kind of a random sound - I'm trying to think of a way. Do you want to control the speed of it by hand?

No not random I need to control the frequency of the cliks.

 

[4pyros]

Here's a discussion of a fake Geiger circuit which uses a short μP program to generate the random sound.

Thats just what I need but I dont think I have time to learn progaming.
I would like to do the same thing with discret components.

 

[4pyros]

Just got back from 3 days at the haunt.

Thanks for all your ideas so far.

Do you think I can get a varible click sound out of a 555 timer?

 

[ericgibbs]

Just got back from 3 days at the haunt.

Thanks for all your ideas so far.

Do you think I can get a varible click sound out of a 555 timer?

hi,
Yes, use a thermistor in place of timing resistor, the operator by placing/changing his finger pressure on the thermistor could vary the click rate.

 

[4pyros]

Eric;
That sounds like a good idea.
Any idea how to get a click out of a 555?

 

[4pyros]

Dah; I am now looking at Electronic Metronomes using 555s.

 

[ericgibbs]

Dah; I am now looking at Electronic Metronomes using 555s.

Any short pulse into a small speaker , via a capacitor will make a click sound

 

[4pyros]

Found this one online https://www.eleccircuit.com/small-metronome-using-2n3904/
Think it will work?

 

[alec_t]

No not random I need to control the frequency of the cliks.

But a Geiger counter's clicks ARE random. Unless you control the frequency so that the clicks are random but their average repetition rate can be increased and decreased they won't sound natural.

 

[alec_t]

Try this perhaps?

Explanation:
The outputs of two oscillators (U1a, U1b) with non-harmonically-related frequencies are ANDed (U1c,U1d) and the result differentiated (C4,R5) to give pseudo-random pulses for driving a speaker. The average frequency of both oscillators is dependent on the resistance of the LDR. In the light the average is low. In the dark it is higher. U1c and U1d are connected in parallel to share the current needed to drive the base of Q3.

 

[4pyros]

But a Geiger counter's clicks ARE random. Unless you control the frequency so that the clicks are random but their average repetition rate can be increased and decreased they won't sound natural.

Yes ideally the clicks would be random, so I would need to increases the frequency of randomness to fatefully simulatet a Geiger counter.
But that may be to much to do with discret components in a weekend.

 

[4pyros]

Try this perhaps?

Explanation:
The outputs of two oscillators (U1a, U1b) with non-harmonically-related frequencies are ANDed (U1c,U1d) and the result differentiated (C4,R5) to give pseudo-random pulses for driving a speaker. The average frequency of both oscillators is dependent on the resistance of the LDR. In the light the average is low. In the dark it is higher. U1c and U1d are connected in parallel to share the current needed to drive the base of Q3.

Thats vary interesting. I will have to see if I have a NAND schmitt trigger chip around here and try it. Thanks

 

[4pyros]

Thats vary interesting. I will have to see if I have a NAND schmitt trigger chip around here and try it. Thanks

Alec;
I tried your circuit but did not like it.
It was not vary loud and had a lot of parts.
And I still needed a way to trigger it.
So......