Understanding the pulse rating of an SCR

[ZeroResistance]

I am looking for an SCR for ignition coil discharge application.

What I would be interested in is the Itrm which is defined as

ITRM
Repetitive peak on-state current
This is the maximum allowable repetitive peak current for a specified pulse
duration at a specified case, ambient or lead temperature and frequency.

however when I look in the SCR datasheet, for example this www.nxp.com/documents/data_sheet/BT151-800R.pdf one I find that the rating specified is of

ITSM
Non repetitive surge peak on-state current
This is the maximum peak current allowed in the device under pulse co
For TRIACs, it is defined for a single full cycle sine wave of 20 ms corre
to the 50 Hz mains, and 16.6 ms for the 60 Hz mains.
If the absolute rating is exceeded, the component may be damaged

Is there a way to derive the Itrm from Itsm, I mean how would one determine the repetitive pulsed current rating of an SCR?
Any help would be high appreciated.

ZR

[Marco]

But that datasheet has them both ...

[ZeroResistance]

The graph at the bottom left of page 3/11 is that it? Its called Fig 1.
I don't know how I missed it.

[danadak]

If you can get your hands on GE SCR handbook that might be useful.


https://www.amazon.com/Manual-Including-Triacs-Other-Thyristors/dp/0137967632?ie=UTF8&*Version*=1&*entries*=0


Maybe there is a pdf scan of it online.


Regards, Dana.