MoTeC Global Forum

Hi guys,
I am a french student and I work on the following project : study of a spray injector.

A colleague see to the chamber and I see to the electronic part.

For ECU, I choose M4 because I think it is sufficient for our needs. I have a question about the type of triggering for injection with the ECU. I want to send a square signal (high time : injection). Can I use the digital input of the ECU and with which voltage (1-5V or 5-20 mA for example).

Hi Seb,

To make the ECU fire the injector you must connect the signal to the REF input and a 0 - 5V square wave is fine. Altho it's not just as simple as one pulse equals one injection event and not Pulse Time = Injection Time.
The ECU needs a number of pulses to calculate RPM and synchronise it's timing clocks before it will fire an injector, then it will hold the injector open for the amount of time it calculates from the fuel tables you have set with a maximum of 61.6mS per an event.
There is also a Test Outputs function where you can set a frequency and duty of the injector and start and stop with a key of the connected laptops keyboard.

Does this suit your needs?

This suit my needs. Thanks for your quick answer.