To get you in the ballpark let's make some assumptions
Hfe of transistors is >= 100 at operating current
left transistor we will call Q1 the other Q2
current for Q2 will be close to (35-1.2) / R2
find the Vbe for Q2 at that current
I will be Vbe / R1
This will get you within a couple of % of what you need.
one more assumption: Q1 can handle the power dissipation and the SOA for your requirements
If Hfe is not that high you will have to look at current paths and do some adding and subtracting
hope that helps
Hfe of transistors is >= 100 at operating current
left transistor we will call Q1 the other Q2
current for Q2 will be close to (35-1.2) / R2
find the Vbe for Q2 at that current
I will be Vbe / R1
This will get you within a couple of % of what you need.
one more assumption: Q1 can handle the power dissipation and the SOA for your requirements
If Hfe is not that high you will have to look at current paths and do some adding and subtracting
hope that helps
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.