Pwm controlled constant current circuit for laser driving

169

02:27:18

Pwm controlled constant current circuit  for laser driving

published 10 years ago

billoute720

10 years ago

Nice but what is the use of the central transistor ?

hurz

10 years ago

The two right transistors are the current sink. Were the central transistor gives a negative feedback to the right one. If voltage above current sensing 10 Ohm is above ~600mV it drops the base voltage to the right transistor. The left transistor disables/drops the base voltage to switch the current sink off. Hope this helps.

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