Frequency to Voltage Convertor

[ccrunner84]

I'm trying to log ethanol content using a flex fuel sensor, however it doesn't provide a 0-5V DC signal but it does provide an output frequency.  I've googled and found that this is possible but I don't know where to even begin after reading a few threads.

Are there calculators out there?  I'm trying to convert say 50–150?Hz into 0-5VDC.

Thanks

[FrankenPC]

Use a small microcontroller?  Read the pulse in and convert to 5V with a DAC out??

[fcb]

LM2907 (National now TI part).

F>V converter IC.

[leppie]

Counting pulses is surely easier and more accurate than converting it to a voltage and then reading it with an ADC (at least in terms of a microcontroller).

[fcb]

I agree counting pulses would more straight forward if the OP wants to design the whole logger from scratch.  It's quite possible they just want to use a COTS logger though.

The LM2907 can be at least 0.5% accurate, so probably good enough for their application.

[electronics man]

How about this http://www.rapidonline.com/electronic-components/lm2917n8-frequency-to-voltage-converter-34504

[ccrunner84]

Thanks for the replies, I'll look at some of these links later today.  I'm not looking to design a logging device, just need a 5V signal to provide to one.

[David Hess]

Counting the frequency is almost always a better solution but there are several ways to do frequency to voltage conversion.  The easiest are to either gate a current source or charge into an RC filter.  The precision way is to use the input voltage of a phase locked voltage to frequency converter.