There has also been a long running discussion of spark gap modelling on the LTspice group.
Using spice to model sub-sections individually can be very quick and useful, that is what spice was designed to do. The problem is that users get carried away and try to integrate the entire project into one simulation. It is not surprising that a simulation will be very slow when 10 seconds of project time is simulated with a time step of 10nsec simply because there was a digital component present in a small part of the simulation.
An accurate spark gap simulation is a problem because it has nanosecond breakdown followed by a one second recovery. The triggering of spark gap breakdown, as a load, can be done with a zener diode and SCR structure. The result of the spark gap breakdown, as a source, can be simulated by a voltage step. The problem comes when the two are coupled into the same model. The simulation needs to be split into two independent modules, one on each side of the spark gap.
Do not do all at the start. You should use a simple circuit at the start of modelling.
Why do you specify and use IRFF230 ?
I will take me some time to make a .MODEL IRFF230 VDMOS( . . . )
Use another model until IRFF230 is available. I use IRFH5300.
The IRFF230 is in a TO-205AF (TO-39) package. It has low power.
A Mosfet is low power only when zero current with voltage, or zero voltage with current.
Your mosfet circuit is unusual. You must use pulse control of the gate. I have changed the circuit.
I have LTspice. See the attached circuit.
When M1 turns on, R1 limits the current through the transformer primary to Ip = V1 / R1 amp.
When M1 turns off, D1 conducts current through L1 to prevent voltage spike.
I do not understand your switch connections.
yi ru huang
thanks for your apply
It is circuit from paper
I want to simulate this circuit with pspice.
This switch is spark gap switch.
But i do not know how to do
i am not a Electrical Engineering student ,so i am very confused about that
What is Discrete EFI ? Is it for high speed flash photography ?
I can model the circuit for you. But I need more information.
Please post a link or attach the paper with the circuit diagram.
The circuit cannot be modeled until design is finished.
High voltage to trigger spark gap. Comes from a pulse transformer with high turns ratio. 1 : 50 ?
Design of transformer. Requires specification of spark gap device part number and data sheet.
Have you selected a three terminal spark gap component ?
What is part number for three terminal spark gap ?
Here are some spark gap examples and data.
Start with application note download; AN-TG-10 Use of Triggered Spark Gaps.
AN-TG-20 TX Miniature Triggered Spark Gaps Description and Use.
Also; Datasheets; TX Series Datasheet. Selection Guide; Three-Electrode Triggered Spark Gaps
AE = adjacent electrode? Adjacent to trigger = main electrode.
OE = opposite electrode? Opposite to trigger.
The MT4206 pulse transformer was used for original simulation.
It has only 1:1:1 turns ratio. It cannot be used for real circuit.
The trigger voltage must be HV, maybe 1kV. So turns ratio must be 25V : 1kV = 1 : 40.
Spice transformer ratio is set by inductance.
Inductance is proportional to n^2. So 1 : 40 turns ratio is 1.0uH : 1.6mH.
Attached is simple spice model of circuit and switch.
It shows same response as Fig 7 of Baginski Et Al. Micromachined Planar Triggered Spark Gap Switch.
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yi ru huang
Thanks for your reply very much.
I tried,but my result is wrong.
I am not sure what the mistake i made
Can you give me suggestions about this?
thanks for your help.
(I do not have .ilb of IRFH5300.)
The design of the EFI trigger pulse transformer is never openly discussed.
Patents show “pulse transformers” and “piezoelectric transformers” being applied to EFI.
Attached is the Perkin Elmer documentation for spark gaps and trigger transformers.
The JAN TX 2N6798 is referenced in US documents because it is a military specified device that works in this application.
There are now better MOSFETs available without mil-spec. They are faster and have lower resistance.
Mini-Triggered Spark Gaps and Transformers, Perkin Elmer.pdf
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yi ru huang
Thank for information of spark gap and EFI you provide
I think I need a little time to read this information.