External ignition amplifier connection - subpage of MembersPage/ChrisGerhardt/ChrisNotes
I bought a large capacitive discharge ignition (CDI) amp to strengthen my spark delivery, but help is needed to connect it (and make it work)
Chris, several signs indicate that Mallory forgot to put a capacitor on the input. The fact that the manual say that you MUST keep the capacitor in a points setup is proof enough. Getting a points capacitor and fitting it between the trigg wire and gnd will most likely solve the problem. -Jörgen
Between Trigg wire and GND? If a missing capacitor causes the problem, I'd bet the capacitor must be in series (so the trigg wire does not directly connect to ignition module, but through a capacitor. Value is a good question, the minimum I'd try is 10uF).
for further progress more info needed on this "ignition box"
- exact pin count
- wire-colors and wire thickness
- any other info known about the signals (name, nickname)
- maybe photo
- brand name Mallory
- part number - sounds like the type is known just not written at the correct place
- make
- link to known docs - sounds like docs are found just forgotten to take note of
- when talking about pins and functions, use bullet list where possible, and use the same naming all over the texts, otherwise they become tangled and unclear
- if you cannot yet match the wires to signals (due to limited docs), as a starting make 2 lists (that we'll try to match, of course) eg.
- one will have pin position and wire color and measurement info
- while the other will have functions
info from unknown source
- external ignition amplifier needs a "coil-type" crank trigger signal
- sounds weird. Most common type of crank trigger, the 60-2 multitooth VR would surely not correctly trigger the external ignition amplifier.
- connecting crank trigger to the "external ignition amplifier" sounds like losing control over ignition advance (MAP independent advance ?). Sounds very bad for a turbo engine.
TODO: redo these. This is just an experiment to extract info from unclear texts; use bullet list as suggested above
- assumed: GND signal
- assumed: switched VBatt power?
- TODO: is this the same as "standard(non crank trigger) input" ? purple has 0VDC (With key on, but engine not running)
- I wired the IGBT directly to the standard(non crank trigger) input of the ignition box that is designed to be triggered by pulling to ground. However, the ignition box does not "see" the trigger and will not work like this. If the signal was 0V in the first place, pulling to ground does not have any effect. In that case a (say 1 .. 4.7 kOhm) pullup resistor must be installed.
- TODO: is this the same as "crank trigger input" ? green wire has the 4.8V DC (With key on, but engine not running). This means that there is an internal pullup resistor (to appr. 5V). You can safely leave any external pullup too, it makes no harm. Another pullup just makes pullup stronger (eg. two pullup of 10kOhm equals - effectively one pullup of 5kOhm).
Testing
Cranking the engine is not necessary,
- make a spark-gap
- from sparkplug - but don't hold this in hand
- or from wire appr. 1..2mm from engine GND: the spark will go from the wire to the GND at the shortest path (again: you don't want to be the shortest path, and anyone with pacemaker does not want to be close at all)
- mdn01 will emit one spark (using configured dwell and VBatt: normally visible and hearable) on ignition channel h[2]=.. xx .. .. .. .. .. ..