A page in the 'IC Timer Cookbook'. On item 'B' is an NPN the correct transistor? The diode seems to be keeping current from getting to the base. If this was a PNP setup, I would understand it. A 2N6055 is NPN.
It might be a 2N3055, one of the most used transistors ever, but we can't tell because we don't have the book. If you post a drawing of the circuit you might get some good answers.
It might be a 2N3055, one of the most used transistors ever, but we can't tell because we don't have the book. If you post a drawing of the circuit you might get some good answers.
The 680 ohm resistor is supplying the base current so this Darlington transistor is normally on. The timer is in charge of shutting it off by dumping the base current through the diode.
The reason it might look strange is that the transistor is a Darlington, but the schematic symbol does not show that fact. A Darlington transistor has a higher Vbe than an ordinary transistor. With the base at 0.7V the Darlington transistor will be OFF.
Yeah, in the 'A' the 'out' was high, so when I looked at the 'B' I presumed it was high again. But no, it was low. No fair changing these things without telling someone.