[sdiy] Help! LM566 alternate?

[Scott Gravenhorst]

"Paul Perry" <pfperry at melbpc.org.au> wrote:
>I don't remember the CD4046 waveform being very regular.
>..any one looked at it lately?

The waveform of the output is actually just a square.  However, you can use a high input
impedance amplifier to get the cap voltage - and that is weird.  It's weird because the
internal switches alternately ground one side of the cap and then the other and inject
charge current on the opposite side.  Our infamous Bjorn
Julin/Nillson/and-several-other-monikers designed an FET input opamp adder that can
construct a sawtooth from the weirdness on both sides of the cap.  The resulting
sawtooth is twice the frequency of the square wave output.

>paul perry melbourne australia
>----- Original Message ----- 
>> But if you wanted to try that, perhaps better using a CD4046 for a simple
>> VCO instead and enjoy much wider range using small film capacitors, no
>need
>> for electrolytics.
>> Just a thought.
>> Mike
>>
>

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