Hi,
I made the circuit at protoboard, I used the first circuit posted. I put 2 potentiometers to get and adjust the output signal instead of R1. Right, everything worked at protoboard so I made a circuit at prototype board, everything soldered and using the same components. The fact is I have an output perfectly at pin 7 but is not switching my transistor to get final output PWM. I supply 9V for IC and 3,3V for transistor. I tested:
- Complete circuit is OK, in fact I have output at pin 7
- Use another transistor but same problem
- Change 555 but same problem
- Change power at both power supplies
- Use an external PWM signal generator with a 12V bulb and same transistor, just to check transistor working, it works.
- Connect pin 7 directly to gate instead of 330 ohm resistor I put, same problem
- Replace 1K resistor by 470 ohm resistor as a final load (instead of motor at scheme)
I don´t know why if I have a proper signal at pin 7 now I don´t get the transistor switching, it worked perfectly at protoboard (without soldering) so next step was to make the circuit soldered... It´s a mistery, maybe you have some new idea because now I´m blocked about this stupid problem.