Frequency to voltage converter

[neo]

Hey all,

seeing we have some electro-savy people here, can someone come up with a circuit diagram / setup that can be used to turn pulses/frequency (Speedo signal) to 0-5v.

I'm trying to hook up an Innovative LM2 to do logging of speed seeing I have some additional channels free - and the only pulse driven input is for the tacho.

I'm yet to investigate how many pulses per km/ revolution it needs, but that will be next.

[blindnz]

What sort of shape wave form do the speed sensor output?

[MAGN1T]

http://www.national.com/ds/LM/LM555.pdf

Steve

[neo]

555's can convert voltage to pulses from what Ive been reading, I need to do the oposite (data logger can only measure 0 - 5v)

I assume its a square wave from the speedo sensor

[Toymad]

Try this one:

http://www.national.com/mpf/LM/LM2917.html#Overview

The page also has the spec sheet.

[Boost_4_Life]

is the square wave 12V or 5Vp-p? if its 5 you can just use a resistor and a cap, we do it with some of our industrial electronics to convert a pwm drive signal to analog. bit basic but it will work.

[pc]

You want to convert a digital pulse into an static voltage 0-5V, with the voltage reading representing the frequency... to log the data in a device that only has free analogue inputs?

Can do lots of things with an arduino, will that do the job? You also do all the logging in it to an SD card.

[MAGN1T]

555's can convert voltage to pulses from what Ive been reading, I need to do the oposite (data logger can only measure 0 - 5v)

I assume its a square wave from the speedo sensor

I knew it would be over your head.

A 555 in monostable mode will trigger off the input and give a PWM output, the duty cycle is dependant on frequency. You then use an RC filter to give an analogue output.

Steve

[Boost_4_Life]

A 555 in monostable mode will trigger off the input and give a PWM output, the duty cycle is dependant on frequency. You then use an RC filter to give an analogue output.

Steve

oh yea i missed the whole frequency thing in my solution! what you say is true.