Gotcha. LEDs are hetero junction, yielding more than a diode drop.
On 3/25/2012 5:05 PM, David wrote:
On Sun, 25 Mar 2012 16:39:57 -0700, gary<[email protected]> wrote:
I'm not so sure about the circuit. The base drive on Q3 is more of less
AC given that the resistor can only pull current out of the base. That
is, I don't see a DC bias on Q3.
R7, R8, and LED D2 sets the base voltage at about 1.8 volts through
R4. Subtract Vbe and Q3's idle current will be about 36 milliamps set
by 1.2 volts across the 33 ohm emitter resistor.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
