Patent ID: 8876769

Claim:
A medical infusion system comprising: a control signal generator; a safety circuit; a switching device; and a pump motor, wherein: the pump motor and the switching device are connected in series and constitute a power supply circuit to be connected to a power supply, the control signal generator is configured to generate a control signal having an “on” potential and an “off” potential present at a control input of the switching device, wherein the “on” potential is any potential which makes the switching device close the power supply circuit, and the “off” potential is any potential which makes the switching device open the power supply circuit, an output of the control signal generator is connected to an input of the safety circuit, an output of the safety circuit is connected to the control input of the switching device, and the safety circuit is configured to apply the “off” potential to its output if there is an “off” potential at its input, apply the “on” potential to its output if there continuously is an “on” potential at its input for a duration up to a predetermined amount of time, and apply the “off” potential to its output if there continuously is an “on” potential at its input for a duration longer than a predetermined amount of time.