JPH0361085U - - Google Patents

Description

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing an embodiment of the present invention, Fig. 2 is an equivalent circuit of an N-type power MOS FET with a current terminal,
FIG. 3 is a time chart showing changes in the load current flowing through the electric motor of the power window device. 1...Microcomputer, 1a...A/D
Converter, 2...Power window switch, 3
...Input interface, 4...Transistor for rising operation, 5...Transistor for falling action, 6...
...Power supply, 7...Grounding point, 8...Bridge circuit, 8
a, 8b...P-type power MOS FET, 8c, 8d...
...N-type power MOS FET with current detection terminal, 9...
Electric motor, 10... detection circuit, a... rising signal, b... falling signal.

Claims (1)

[Scope of utility model registration request] A control circuit for a power window device for an automobile is configured to operate an electric motor forward or reverse when a power window switch is operated to the up or down side to raise or lower the window. A transistor for rising operation in which the collector terminal potential is switched from the power supply potential to the ground potential by operating the switch on the rising side, and a transistor for descending operation in which the collector terminal potential is switched from the power supply potential to the ground potential by operating the power window switch in the descending direction. The drain terminals of the transistor and two P-type power MOS FETs whose source terminals are connected to the power supply are connected to the respective drain terminals of two N-type power MOS FETs with current detection terminals whose source terminals are connected to the ground point. The electric motor is connected between both connection points, the gate terminals of the P-type power MOS FET whose drain terminals are connected together and the gate terminals of the N-type power MOS FET with a current detection terminal are connected, and both connection points are connected to the above-mentioned connection points. Calculated from a bridge circuit connected to the respective collector terminals of the rising operation transistor and the falling operation transistor, and the detected current detected at the current detection terminal of the N-type power MOS FET with a current detection terminal that constitutes the bridge circuit. Find the value of the current flowing through the electric motor, and if the duration of the current value exceeding a preset value is within a preset time, it is determined that it is an inrush current of the electric motor. , a microcomputer that diagnoses the failure of a power window device in real time by comparing the transition of the current value during the period from the fully open state to the fully closed state with the current value transition in a normal case determined by measuring in advance; A control device for a power window device for an automobile, characterized by comprising: