Real time freq correction problem

[Rosco101]

Hi All

Hopefully some bright spark can assist me with the following problem.

I’m looking for a simple method to perform a real time frequency shift to correct an electronic speedo.

The sensor outputs a 12v square wave signal to the speedo

I looking for an adjustable range of around +/-12% with a resolution down to .001%, this will allow me to experiment with various gear ratios.

Commercial products are available for $100-$200, like Yellow Box or Speedo Healer but I was hoping to avoid the cost and I enjoy building projects.

Any suggestions or cct diag ideas would be much appreciated.

I am also building a shift light, fairly simple overspeed cct using a latching freq to volt converter. And a gear position sensor for which I’m thinking of modifying an expanded scale led volt meter (my bike has a gear position sensor for the fuel computer) to drive an LCD display. A little rough but it may work.

I don’t usually use this type of forum as I don’t have much to contribute in return (guilt) but hopefully someone can assist.

Cheers
Ross

 

[Russlk]

Hi All

I’m looking for a simple method to perform a real time frequency shift to correct an electronic speedo.

The sensor outputs a 12v square wave signal to the speedo

I looking for an adjustable range of around +/-12% with a resolution down to .001%, this will allow me to experiment with various gear ratios.


Ross

The only solution I can think of is to use a frequency-to-voltage conversion and voltage-to-frequency. ICs are available.

 

[Rosco101]

The only solution I can think of is to use a frequency-to-voltage conversion and voltage-to-frequency. ICs are available.[/quote]

Not a bad idea at all!

Using DIP switches to add or subtract various resistors in between the two
converters might just be the ticket.

Thanks
Ross