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Voltage split/reduce voltage output of 555 timer

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antknee

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I have the set up in the picture below, both the 555 timer and amp work just fine. The amp datasheet lists the use of a 10K pot as a volume control in series with a 1K resistor and so the setup itself is ok. The problem I have is that I only want 1Vpp and the 555 timer outputs 2Vpp when it is supplied with 2 AA batteries. I can't use just 1 AA battery because the 555 timer wants more volts and won't work. So how do I get just 1Vpp output?

It occurs to me that I could put a resistor in parallel somewhere to split the voltage, but I'm not sure where or what value to use. It also occurs to me that the 555 does have a pin called voltage control and perhaps I could do something with that to output just 1Vpp, but I wouldn't know how.

What would you suggest?

Thanks.

s6308397-jpg.43396
 

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An ordinary 555 has a minimum supply of 4.5V and will not work with only 3V or less from two AAA cells. A Cmos 555 works fine from 2V or 3V so maybe you have a Cmos 555.

Your 10k pot is not connected like a volume control. It should not need the 1k resistor and should be connected like this:
 

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The 555 I have works fine with 2.5V DC supply and the datasheet for the amp says use a 1K resistor in series with the pot.

I think to halve the voltage I need a 1K resistor in parallel to the one already there and going to earth on the 555.
 
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If you turn my audio-taper volume control to a little less than max then the voltage from the slider is half the input.
My volume control is an adjustable voltage divider. Its output is adjustable from nothing to the input voltage.
i don't know what your resistors do but they do not make a volume control.

Which amplifier do you use that needs a 1k input resistor?
 
The volume control works just fine. It provides 0-2V from the 555 with one full turn of the pot. I realise I can just turn the pot half way but if I input more than 1V I risk cracking my piezo. So I want to output 0-1V rather than 0-2V.

I just put another 1K resistor in parallel with the first except going to earth rather than the amp, no luck.
 
This should work, depending on your amplifier, which you have not described.
You may need a capacitor in series between the 555 and the 10k resistor.
 

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