tremblaylaroue
Newbie level 3
inductive ignition circuit
I want to build a circuit that will pick-up induction from a pulse generated by an engine sparkplug and create a nice digital signal from it...
The trick is to wrap a wire about 10 turns around the sparkplug wire.
The problem is that I don't know how to filter this noisy signal.
The maximum spark duration will be 0.5 ms.
So I need a circuit (very sensitive but well protected) that will detect a voltage surge, produce a ttl level signal from it and maintain it for 0.5 ms to filter out outer spikes produced while spark is occuring.
Someone suggested me to try to put a low-pass filter (L-C) to filter out all HF noise and then a Schmitt Trigger gate or a monostabile to form nice pulses from what is left after LPF, but I don't know how to select the good components...
I searched on the web for a digital inductive tachometer schematic and related stuff without succes.
Any help will be apreciated !
Dany
I want to build a circuit that will pick-up induction from a pulse generated by an engine sparkplug and create a nice digital signal from it...
The trick is to wrap a wire about 10 turns around the sparkplug wire.
The problem is that I don't know how to filter this noisy signal.
The maximum spark duration will be 0.5 ms.
So I need a circuit (very sensitive but well protected) that will detect a voltage surge, produce a ttl level signal from it and maintain it for 0.5 ms to filter out outer spikes produced while spark is occuring.
Someone suggested me to try to put a low-pass filter (L-C) to filter out all HF noise and then a Schmitt Trigger gate or a monostabile to form nice pulses from what is left after LPF, but I don't know how to select the good components...
I searched on the web for a digital inductive tachometer schematic and related stuff without succes.
Any help will be apreciated !
Dany
