J&S V2 Vampire with rev limiter

[@jselectronics8215]

The Vampire is for direct ignition with dumb coils. To install, no wires are cut or intercepted. The stock inductive ignition remains in place and does most of the work. The Vampire goes active only to retard, or to rev limit. The Vampire retards by extending dwell, and rev limits by swallowing the flyback pulse and the current from the collapsing magnetic field in the coil.

[@shortedtoground]

Is the Vampire 2 able to swallow the current through the primary wires? (this version 2 is awesome by the way). I love your testing set up too.

[@jselectronics8215]

@@shortedtoground Yes, the Vampire "control wires" connect to the coil negative of each coil. The charged coil is like a hot potato. If you drop it, you WILL make a spark. When the rev limit trip point is detected, the rev limit transistor turns on hard, killing the flyback pulse. Then it is slowly turned off, effectively turning the transistor into a load resistor, allowing the energy stored in the coil to bleed off in a controlled manner. Only then can the transistor be turned off. Otherwise the coil will try to make a spark.