dealing with pulses?

Hey guys, I'm swapping out my cluster for a G37 cluster because it looks so much better but I'm having an issue regarding the speedo.

It appears that the G35 uses a 2 pulse speed signal, and the G37 uses an 8 pulse speed signal. Would anyone here have some insight on how to deal with it?

Thanks guys! I know many of you here are guru's at this kind of stuff lol.

Usually the information they give you is the number of pulses per a given distance.  Short of adapting the device that generates the pulses, I really see no way you will be able to pull this off.

Division is easy.
Multiplication difficult - except sometimes x2 where you edge-trigger each pulse.
Above that gets messy if evenly spaced pulses are required. In old days PLLs (Phase-Lock Loops) were used; these days digital.

If spacing is not a problem, have each edge trigger two pulses, hence 2 pulses becomes 8.

Otherwise find out what is supplying the pulses and maybe modify that.

oldspark wrote:

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Division is easy.
Multiplication difficult - except sometimes x2 where you edge-trigger each pulse.
Above that gets messy if evenly spaced pulses are required. In old days PLLs (Phase-Lock Loops) were used; these days digital.

If spacing is not a problem, have each edge trigger two pulses, hence 2 pulses becomes 8.

Otherwise find out what is supplying the pulses and maybe modify that.

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I was thinking the same thing, I'm not too sure if a gap would effect much but it's worth a shot. How would I get it to trigger 2 pulses each?

Calc your max speed and hence max pulse rate and have each edge trigger a 2-shot pulser...
Though it's easier following the first edge-trigger with a second where each edge-triggered output is less than the max (speed) pulse rate duration (draw the pulses and figure it out).
IE - the single original pulse feeds a +ve edge trigger and a -ve edge trigger (hence x2 pulses). Each of those feeds another + & - edge trigger (another x2). All outputs are combined (ie, OR'd - if parallel circuits) and must be adequately spaced to get x2x2 = x4 pulses from the original 1 pulse.

Or maybe use a clock at twice the max pulse rate to clock a 4017 counter set to count to 4... (leave "0", diode-OR outputs 1,3,5,7 together, "8" to reset, and need speedo pulses to trigger one sweep per pulse..... (sorry, just thinking aloud but with zero ROM)