Kris:
Thank you for the adivise. I'll add a resistor to the design as suggested. So a 1/4 W, 470 ohm resistor must be enough then. Again thank you and CDDRIVE for the help.
PD. I'm a new guy to the discussion. Re starting my electronics after 20 year of not working on this. Long time away...
CDRIVE:
Thank you for your so helpfull suggestion. I'm doing something like that. But really required less current as capable of providing th 2N3055, so I'm switching to a TIP31C which support 3A, enough for my project. I do have a question about your circuit. Your diagram shows RL on the...