Control circuit for a DC motor

A control circuit for a DC motor, comprising:

• a first DC port and a second DC port for connection to a DC source;
• a H-bridge driving circuit, comprising a first switch and a second switch connected in series between the first and second DC ports, and a third switch and a fourth switch connected in series between the first and second DC ports, a first output port lying between the first and the second switches and a second output port lying between the third and the fourth switches, the output ports being arranged for connection to the DC motor;
• and
• a blocking circuit connected in series with the DC motor between the first and second output ports and having a resistance that will increase in response to a BEMF generated by the DC motor.

A control circuit for a DC motor, comprising:

• a first DC port and a second DC port for connection to a DC source;
• a H-bridge driving circuit, comprising a first switch and a second switch connected in series between the first and second DC ports, and a third switch and a fourth switch connected in series between the first and second DC ports, a first output port lying between the first and the second switches and a second output port lying between the third and the fourth switches, the output ports being arranged for connection to the DC motor;
• a shunt circuit connected between the first and second output ports and having a resistance that will decrease in response to a BEMF generated by the DC motor;
• and
• a blocking circuit connected in series with the DC motor between the first and second output ports and having a resistance that will increase in response to a BEMF generated by the DC motor.