Reducing the frequency

[orwikcons]

Greetings!

I have a problem in my car with the speed giver. It gives larger speed than I drive. So I would like to put something to correct the problem. It sends a mass frequently, so when the transmission makes one revolution, one half of revolution the mass is sent through the signal, and the other half the signal is empty, sa as the car moves, the signal is frequently rotation of mass/empty. I hope that I gave a conceivable explanation...

I need a device which will make the frequency reduced for a rational coefficient (not integer), about 1.123. Input signal is the frequency from giver, and output signal is a frequencu multiplied for a coefficiente. Can it be made?

 

[Sadegh.j]

Have you tried an A Stable. It should not be that easy though.

 

[VVV]

It is pretty hard to believe the transmission is sending out the wrong number of pulses, as there are only mechanical components inside. I would double-check that before doing anything.

A fractional PLL could be a solution, but it is not easy to implement.

Perhaps it is easier to have a micro measure the frequency, calculate the corrected one and output it using a PWM.

 

[orwikcons]

Well, I didn't mention that I have put the cluster from other car into mine (from VW Golf 4 to Golf 2), and the reason of showing a wrong speed is because the difference between wheel's diameter of these two cars.

Now, what is PWM?

 

[A.Anand Srinivasan]

PWM is pulse width modulation... it is the variation of the pulse width based on the input.....

 

[ameed]

Well, I didn't mention that I have put the cluster from other car into mine (from VW Golf 4 to Golf

2), and the reason of showing a wrong speed is because the difference between wheel's

diameter of these two cars.

PWM or freqency divider is also useful.

thanx.