wanting circuit to connect car EFI to spark module.

[Peter Miller]

Hi, happy to finally find a forum that may help me (and others I believe) with an auto electrical issue.
I believe I need something akin to a Schmidt circuit, but dont know how to build it or what specific value(s) of components to use.

Situation is; I have a Powerjection 3(with spark control) EFI. It puts out a Hall effect type output signal to drive a spark module. Signal is 12 volts positive and fires on the trailing edge of the square wave, when it goes to 0 volts each time.
I have choice of a MSD6 and a Jacobs Electronics mileagemaster spark module. They have a positive 12 volt (white) signal input wire that generates ignition spark(s) "after" one grounds it (i.e. when one takes it away from a ground to give it an open circuit each time). Hope I am making sence here.

I need a circuit to allow them to "talk" to each other. Greatful and thanks for any help & advice with my dilema.

 

[Dr_Doggy]

im not too sure what you mean about Hall effect output,

if i get you though , you are saying:
you have a Fuel injector that has an output of 12 v that goes to 0 on a trigger and has spark control

you have a Distributor(spark system) that fires on a negative trigger, that goes from 12v to 0 on the input

sounds to me that they are made for each other, maybe let them touch a bit!? , maybe wear insulated gloves

testing the spark system by using ammeter on trigger will show if there is high current on trigger(which could then be a problem)

but this is advice from someone with little experience in either field

 

[Peter Miller]

Hi and thanks for reply. Right regards EFI. The spark system however, has a signal input wire that has an "outward" 12 volts (i.e it tests as positive). When one touches it to earth & then takes it away from the earth it generates a spark, but only when one takes it away. In other wods when the circuit goes open after earthing it.
It has been suggested to me to simply use an "inverting hex buffer" Cat ZC4009 and type 4009. Alternatively, the enclosed circuit.
What do you guys think?

 

[Dr_Doggy]

this is simple inverter circuit:
http://www.transtutors.com/university/images/1889_What is Transistor NOT Gate.JPG
http://www.reuk.co.uk/OtherImages/PIR-sensor-transistor-inverter-NOT-gate.jpg