Frequency to voltage conversion

[Darkbluesky]

Hello,

I'm new to these forums. I have discovered this site recently. It is a very interesting site IMO, I like it.

 

[audioguru2]

Hi DarkBlueSky,
Welcome to our forum. ;D
It would be easier to see how you connected your circuits if you attached a sketch, but maybe this site has a problem lately with attachments.

The LM2907-8 needs to have a resistor from its input to 0V, then the signal should be capacitor-coupled to it so that its input signal swings above and below 0V.

 

[Darkbluesky]

Thanks for the answer,

I did not understand very well, actually I do not know what should I do. How are the resistor and capacitor to be connected? How can I calculate the correct values?

Maybe an image or a link to some example should be enough...

I have made a simple schema:

just in case the link above doesn't work, the link to the image is http://www.pix8.net/pro/pic.php?u=6285n7XME&i=856309

Thank you

 

[audioguru2]

The input needs a 100k resistor to 0V and a 0.1uF coupling capacitor like this:
EDIT: Sorry, this site won't let me attach my corrected sketch. It says that my upload folder is full.

 

[Darkbluesky]

could you send it to my email in my profile and I'll post it here.

Should the capacitor be electrolytic?, because I can't found here where I am, capacitors electrolytics of 0.1 uF. I can find of 0.47uF instead.

I can get, though, capacitors of 0.1 uF but of tantalum-type.

btw, if using a 0.47 uF, maybe the 100K resistor should take a different value...?

 

[audioguru2]

Should the capacitor be electrolytic?, because I can't found here where I am, capacitors electrolytics of 0.1 uF. I can find of 0.47uF instead.

0.1uF capacitors are very common. They are metalized plastic film, not electrolytic. They are called "green caps" or "mylar". Frequently they are marked 100nF or 104.
A 0.47uF capacitor at the input will work fine.

I think the attachments are fixed now on this site.

 

[Darkbluesky]

Thank you very much. I have tried it and it works!

 

[audioguru2]

Good, it works. ;D