An H bridge using 2 PNP and 2 NPN bipolar transistors.
The motor speed is controlled with PWM from a 555 timer chip.
Motor spin direction is controlled with the H Bridge.
Capacitor (to filter out the ripple current) and catch diodes are for safety.
The 100Ohm resistor on the output of the 555 chip is to protect the transistors from too high currents.
Short testing of the circuit has been done with FF-050SK-11170 DC motor and BC639 and BC640 transistors.
Nothing burned.
