First sorry for my english. The problem is it looks like MOSFET is not opening completely, and I do not have any equipment except crappy 5$ multimeter. I measured 3 points on the PCB, they are marked on the schematic. What confuse me, is that when I remove motor from circuit, and leave drain not connected to anything, I get 12V betwen VCC and drain, but when I connect the motor, voltage drops. If spinning, the motor consumes ~120mA, also the motor is not rated for 12V, but it's just a test, and I doesn't care. For PWM generating I'm using NE555(here is the datesheet of ne555n
), and for driving MOSFET BC327, and BC337. I wanted to make a high voltage generator, but for tests, I'm using small DC motor salvaged from RC car.