A Test Method of H-bridge Output Waveform Dead Time

Abstract

The present invention discloses an H-bridge output waveform dead time test method. The method comprises the following steps that: a) a first power resistor R1 and a second power resistor R2 are selected; b) the first power resistor R1 is connected in parallel with one bridge arm of an H-bridge, and the second power resistor R2 is connected in parallel with the other bridge arm of the H-bridge; c) the first power resistor R1 and the second power resistor R2 are connected in series and are connected with the grounding end G of the H-bridge, and an oscilloscope probe is adopted to measure the waveforms of the output end T2 of the H-bridge relative to the grounding end G; and d) the measured waveforms are amplified, so that the dead time of the output end of the measured H-bridge is obtained. According to the H-bridge output waveform dead time test method of the invention, the power resistors are connected in parallel with the two bridge arms of the H-bridge, so that the dead time of the output end of the H-bridge can be directly tested; observation and operation can be facilitated; error influence caused by indirect measurement can be eliminated; the dead time of the output end of the H-bridge can be measured effectively and conveniently with no differential probes used; and therefore, the loss of an H-bridge circuit can be lower, and the output efficiency of the H-bridge circuit can be higher.

Description

technical field [0001] The invention relates to an automobile electronic technology using a motor, in particular to a method for testing the dead time of an H bridge output waveform in the automobile electronic technology. Background technique [0002] With the improvement of automobile electronics, more and more electronic components appear in the car. Many of these electronic components use motors as part of the actuator, such as in electronically controlled fuel injection control systems, motors and fuel pumps As a whole, it provides power for the oil supply system. In the power steering system, the electronic control unit acts on the column or the rack and pinion to provide power for the steering system through the motor. It can be said that motors are more and more widely used in automobiles. There are mainly two types of motors: DC motors and AC motors, but no matter what kind of motor, its control circuit is mainly realized through the H bridge. This is achieved thro...

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Problems solved by technology

[0007] The above two methods are commonly used to measure the dead time with an oscilloscope, but both have some weaknesses. Firstly, the two methods indirectly obtain the dead time of the output terminal, and there is a certain error with the actual dead time of the output terminal. Secondly, the two methods Both measurement methods are relatively complicated, and the measured waveform is not easy to observe when calculating the dead time, see image 3 , between the two dotted lines is the schematic diagram of the enlarged dead zone time. It can be seen that when defining the dead zone time, the positions of the two dotted lines can be moved to the left or right respectively, which is not easy to define, so the error is large

In addition, method 2 has special requirements for measuring the test leads, that is, when using the test lead A2 to measure the waveform between the control terminal G1 of the upper bridge arm and T1, the test leads are required to be differential test leads, and the use of ordinary test leads is easy to damage the oscilloscope

[0008] It can be seen from the above that both method 1 and method 2 are indirect measurement methods, and the measured object is the control signal of the power device used in the H bridge, not the real on / off signal of the power device, which is different from the actual There is some error in the dead time of the

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