Koso gauge RPM set up

[McCabe-Thiele (Ted)]

I suspect the impulse measurement signal would be different if it includes the circuit through the coils unless it's designed to work on the feed side as this would not be affected by the coil resistance - your logic to connect on the B&W side makes more sense. Do the instructions help?

[DomP]

The rpm is just the signal wire as the gauge is multifunction so has a supply and ground.  The signal connection is what myself and Roo worked out but could be wrong

[K2-K6]

I wonder if this would work

This is used on many current cars, tapping a phase on alternator to give speed signal of crank. Often on diesel that have no ignition to speak of.

Whether your kit can sense it from there I'd not know.

[McCabe-Thiele (Ted)]

Might be worth trying the impulse wire on the other side if the LT connection a blue say. The signal via the coil  primary windings might give it more signal oomph?
Odd if no details of how many winds round the coil wire is needed in the instructions.

[DomP]

I'll try that Ted, I don't have a blue wire coming from my electronic ignition though, there is one with a blue shrink-wrap.

I'm worried about frying the gauge though.

*Well I threw caution to the wind, tapped into the blue sleeved wire from the Dyna S and got a rev reading!  Not accurate but I can work on that in the settings I think, it was a bit bouncy

[McCabe-Thiele (Ted)]

Is you rev counter designed to work with electronic ignition the switching signal profile might be unsuitable.

As you are dealing with an inducted circuit it might be possible to dampen it. Electronics is not my forte.

[DomP]

It says its suitable for both, I think it's reading around half the revs on setting 2 which is 1 rpm signal per 2 ignitions so u wonder if I change it to setting 4 which is 1 rpm signal per 4 ignitions

[McCabe-Thiele (Ted)]

Deffo try setting 4 then. 👍

[DomP]

I'll give it a try later Ted.  So why don't they suggest connecting it up on the ignition side rather than from the coil I wonder, then again looking at the instructions I'm not surprised.

[McCabe-Thiele (Ted)]

Just a thought might be coil side for CB, other side for Electronic..

[DomP]

Sadly setting 4 made no difference, only getting a reading when I raise the revs

[Bryanj]

1 rpm per 2 signals should be correct i think

[DomP]

1 rpm per 2 signals should be correct i think

That's what I initially thought Bryan,  more research needed I think.  At least I've got it to register some sort of reading

[DomP]

Bring up my old thread as the weather has returned me to tinkering in the garage again, this time I'm determined to sort the rpm signal to my Koso gauge.  I've been in conversation with the europe help desk and this is what they have told me is an alternative set up as neither of their other suggestions work.  The question is are they suggesting I connect to one of the three yellow wires coming from the alternator?  That seems like a recipe for a burned our gauge to me.

[K2-K6]

Looks as you understand it, taking a signal from one of the phases of alternator.

This is quite usual though as many cars run that type. Most diesels with rev counters too as there was no ignition to  read when they were less sophisticated. Many types have moved to running off crank sensor now and via ecu processor.

If that's their stated instructions it should be OK to try with their unit.