A drive port self-diagnosis circuit

Abstract

The invention discloses a drive port self-diagnostic circuit. The drive port self-diagnostic circuit comprises a microprogrammed control unit (MCU), a triode, a field-effect tube, a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor, wherein a source electrode of the field-effect tube is connected with a power supply, a drain electrode of the field-effect tube is connected with a load, a grid electrode of the field-effect tube is connected with a collector electrode of the triode, a base electrode of the triode is connected with a control end through the second resistor, an emitting electrode is grounded, a collector electrode of the triode is connected with the power supply through the first resistor, the drain electrode of the field-effect tube is connected with the MCU through the third resistor, the third resistor is grounded through the fourth resistor, and two ends of the fifth resistor are respectively connected between the drain electrode and the source electrode of the field-effect tube. The drive port self-diagnostic circuit can effectively judge open and short-circuit conditions of a loading device, the circuit is simple, and system faults can be discovered as soon as possible due to the fact that the circuit is in a work state for a long time.

Description

technical field [0001] The invention relates to circuit technology, in particular to a drive port self-diagnosis circuit. Background technique [0002] In vehicle controllers such as automobiles and construction machinery, many electrical devices require the controller to directly provide power to the device when it needs to work. In order to ensure the reliability of the system, the state of the control device is monitored. When the device appears In the event of a fault (short circuit, open circuit), the system must carry out an alarm and corresponding protection actions to ensure the safety of vehicles and personnel. [0003] The general design is to add a complex analog circuit to the control port, and realize the state detection of the port by detecting the voltage. The circuit structure of this scheme is complicated, and the fatal shortcoming is that it can only detect the short circuit state but not the open circuit state. A general implementation such as figure 1 ...

AI Technical Summary

Problems solved by technology

[0004] This circuit can only judge that the load is short-circuited. When the load is short-circuited, the control terminal (MCU_CON) outputs a high level, and the M works. ;When the load is open, when the control terminal (MCU_CON) outputs a high level, the control M is turned on, and the MCU detects that it is a high level. When the output is low, the control M is turned off, and the MCU port is detected as a low level.

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