Ignition pulse

Ignition pulse generator including pulse generator with button, low tension cable, coil electrode and sight glass, if required. 

In dimensionless terms, there is a critical value for S (Damkohler number) that makes ignition possible. From Equation (4.23), this qualitatively means that the reaction time must be smaller than the time needed for the diffusion of heat. The pulse of the spark energy must at least be longer than the reaction time. Also, the time for autoignition at a given temperature T is directly related to the reaction time according to Semenov (as reported in Reference [5]) by... 

Pushing 110V AC on a 12V DC Pulse automotive ignition coil causes some problems ... 

I m using an old Chevy 20,000 volt ignition coil pulsed by a 555 20 Hz 50% duty. This is Just talking about the HV spark. Power source is a 12 volt 8-battery bank. Switching is done by an IRG4P254S IGBT. 

The easiest way of course is to use a small single cylinder engine and use a single-shot plasma discharge system. For example with manually controlled ignition coil or other HV source and pulse capacitor discharge from the flash unit of a disposable camera. 

I tested the plasma ignition system in my 6.5hp 4-stroke engine with gasoline and propane (didn t test water yet). I used HV pulses from the original ignition coil as trigger or pilot sparks. I had to reverse the polarities of the bridge rectifier, two diodes and the capacitor to get a better pilot spark. The schematic and details are ... 

There s a very simple explanation why the spark plug receives a negative HV pulse. In a points-ignition you first make the contact (current starts flowing from the battery to the ignition coil primary) and then after what s called dwell time the contact is broken. The spark is formed when the contact is broken. 

The problem with Sir s design was that the relay was not acting as a relay but was acting more like an open pulsed DC circuit which merely allowed the HV spikes from the ignition coil to piggyback onto the IIOv higher amp circuit to the plugs. This created a plasma arc very similar to that used by arc welders but in short duration pulses. 

Do note that when using step-up transformers (induction coils) that in order to create the high voltage electromagnetic field in them, you must use either AC or pulsed DC current. The capacitor in an induction ignition system does this pulsing. In the above circuit the capacitor is in the inverter (50-60Hz). 

A simpler variation would be to use a normal Hall ignition system where you use the induction pulse to trigger a timing circuit to open the HV combined circuit for a specific period of time. The timing can be simple capacitor based or use a simple 555 1C timer with an adjustable variable resistor used to set the actual timing of the firing period. 

In a pulse of 200 microseconds with a beam width of 1 second, this laser would ignite wood and paper at a distance of about 1 mile Refs 1) D.G. Grant, APL/JHU CF-2974,... 

Under the heading "General Case , Ma ek states (p 47) that in order to solve eq (1) with out approximations subject to specific boundary conditions, one has to resort to numerical procedures. G. B. Cook (Refs 6a 7a) treated two problems by means of calcns with. digital computers. First is the case of a slab of solid expl,one face of which was in contact with. a constant-temp bath. In the 2nd case the expl was subjected to a time-dependent heat pulse. In both. cases the time to ignition and the critical condition for ignition are given as... 

Detn of the tendency of various expls to be ignited by an explosive pulse, is described. 

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