초록 ▼

A motor driver interface (MDI) circuit includes fault detection apparatus effective to detect short circuits to the power supply in the switching transistors of an H-bridge reversible DC motor arrangement. A pair of timers distinguishes a true fault condition. The first timer is responsive to a cont

A motor driver interface (MDI) circuit includes fault detection apparatus effective to detect short circuits to the power supply in the switching transistors of an H-bridge reversible DC motor arrangement. A pair of timers distinguishes a true fault condition. The first timer is responsive to a continuous fault detection to define a first time period from its initiation; and a second timer is responsive to a continuous presence of a transistor conduction signal to define a second time period from its initiation. The apparatus stores a fault signal in response to the detection of the fault condition at the end of the first or second time periods with the first timer providing fault detection upon turn-on after the brief initial high transistor turn-on current and the second timer providing noise immunity.

대표청구항 ▼

In an H-bridge electric motor drive apparatus comprising an electric power supply having supply and ground voltage terminals, a first pair of switching transistors connected in series with the power supply, a second pair of switching transistors connected in parallel with the first pair of switching

In an H-bridge electric motor drive apparatus comprising an electric power supply having supply and ground voltage terminals, a first pair of switching transistors connected in series with the power supply, a second pair of switching transistors connected in parallel with the first pair of switching transistors, and an electric motor having a first motor terminal connected to the junction of the first pair of switching transistors and a second terminal connected to the junction of the second pair of switching transistors, the switching transistors being activatable to a conducting condition in a predetermined combination in response to a first input control signal to connect the electric motor across the electric power supply for motor activation and further activatable to a non-conducting condition in response to a second input control signal to disconnect the electric motor from the electric power for motor deactivation, fault detection apparatus comprising, in combination: means effective to compare the voltage at one of the first and second motor terminals with at least one reference voltage to determine a fault condition; a first timer response to a continuous detection of the fault condition to define a first time period from the initiation of said continuous detection; a second timer responsive to a continuous presence of the first input control signal to define a second time period from the initiation of said first output control signal; means effective to store a fault signal in response to the detection of the fault condition at the end of the first or second time periods.