[lwoodward96]

Hi Everyone

As part of my EFI conversion on a Triumph Stag, I needed an easy way to get a Speeduino compatible trigger for engine speed. So I had some boards made to condition the pulse from a classic ignition coil negative into a 5v square wave. Uses the same schematic as the CoilX board. So has an opto-isolator and inverting trigger to give a nice output. Tested working on my setup but no guarantees made and no liability etc...

Costs meant that I ended up with about 20 of these boards, and only need a couple myself, so they're up for sale if anyone wants one at cost plus postage.

I've listed them on my site https://invisiblefuelinjection.co.uk/sh ... rigger-pcb, use the discount code "speedy" to bring it down to cost price

Connections needed are:

• Engine Ground
  Coil Negative
  ECU 5V
  ECU Ground
  RPM trigger

[jonbill]

don't VR conditioners achieve the same? (genuine question!)

[PSIG]

Yes, but input voltage is limited on some, such as the current MAX conditioner versions. Those for example have a 160V limit on input signal as-is, which is at the low-end for coil(-) flyback. With some calculations, the input shunt and resistors could be configured to reduce voltage in order to make it suitable for coil(-).

The DSC conditioner has shown it can do coil(-) signals along with most other kinds of signals, but like the CoilX I don't know if there is a limit for some high-V and CDI coils. Some of those hit 450V flyback. A search will show discussions we've had on the coil(-) topic in recent years with some design theory and tested updates if you're digging.

[jonbill]

Thanks, just trying to understand more.