Hi guys,
I've designed a single-shot auto-charge flash circuit and like to share with you.
Greetings

 

I'm surprised there's no current-limiting resistor between Q1 collector and Q2 base .

 

Forrest Mims didn't use a resistor there either:


Source: https://books.google.com/books?id=-...v#v=onepage&q=mims: single shot flash&f=false

John

 

Forrest Mims didn't use a resistor there either:

True, but their supply is only 1.5V (not 12V) and their R1=27k (not 4k7), so less chance of excessive base current.