Motor driving circuit

A motor driving circuit comprising:

• first and second transistors of an npn type that are connected between a power line and a ground line with their collector-emitter paths connected in series;
• third and fourth transistors of a npn type that are connected between a power line and a ground line with their collector-emitter paths connected in series;
• means for controlling said transistors to be alternately in a first state where the first and fourth transistors are on and the second and third transistors are off and in a second state where the first and fourth transistors are off and the second and third transistors are on;
• a motor coil connected between a first node connecting an emitter of the first transistor to a collector of the second transistor and a second node connecting an emitter of the third transistor to a collector of the fourth transistor;
• a fifth transistor of a pnp type with its base connected to said power line, its emitter connected to the first node, and its collector connected to a base of the second transistor;
• and
• a sixth transistor of a pnp type with its base connected to said power line, its emitter connected to the second node, and its collector connected to a base of the fourth transistor.

A motor driving circuit comprising:

• first and second transistors of an npn type that are connected between a first power line and a ground line with their collector-emitter paths connected in series;
• third and fourth transistors of a npn type that are connected between the first power line and a ground line with their collector-emitter paths connected in series;
• means for controlling said transistors to be alternately in a first state where the first and fourth transistors are on and the second and third transistors are off and in a second state where the first and fourth transistors are off and the second and third transistors are on;
• a motor coil connected between a first node connecting an emitter of the first transistor to a collector of the second transistor and a second node connecting an emitter of the third transistor to a collector of the fourth transistor;
• a second power line;
• a fifth transistor of a pnp type with its base connected to said second power line, its emitter connected to the first node, and its collector connected to a base of the second transistor;
• and
• a sixth transistor of a pnp type with its base connected to the second power line, its emitter connected to the second node, and its collector connected to a base of the fourth transistor.