Hi,
Welcome to the forum.
Sorry, I don't have time to check your calcs but your approach looks good
.
The 100R sereis input resistor will drop 230mA * 100 = 23V ? ? ?
I needs to be much lower like 5R 5 * 230mA = 1.15V
Use a 1W resistor.
Check your zener specs, I think they provide an current impulse parameter, a 1W zener would be nice and safe.
Not sure if you have seen this project for info?
Tom.... 