Direct-current contactor closing and releasing time detection circuit and method

Abstract

The invention discloses a direct-current contactor closing and releasing time detection circuit and method and relates to the field of contactor circuit technologies. According to the detection circuit, a power circuit is used for converting the voltage of power input into a voltage with an appropriate amplitude to supply power to other circuits; a processor is used for sending control signals tothe power circuit and a fast switching circuit respectively, then controlling a power voltage value and on / off of a switch in the fast switching circuit and acquiring a contact state signal of a contactor so as to detect closing and / or releasing time of the contactor; a switching tube with small on resistance and high speed is adopted in the fast switching circuit, and the fast switching circuit is used for quickly applying a rated voltage of the contactor to or removing the rated voltage of the contactor from a power end of the contactor; a contact opening and closing measurement circuit is provided with a high-speed optocoupler to shorten signal triggering time and is used for detecting the contact state signal and a conversion action of the contactor; and the high-speed switching tube enables voltages to be rapidly applied to or removed from two power ends of the contactor, and the high-speed optocoupler makes a contact test result fast and precise.

Description

technical field [0001] The invention relates to the technical field of contactor circuits, in particular to a circuit and method for detecting the pull-in and release time of a DC contactor. Background technique [0002] Contactors: Contactors are divided into AC contactors and DC contactors, which are used in electric power, power distribution and power consumption occasions. In a broad sense, a contactor refers to an electrical appliance that uses a coil to flow through a current to generate a magnetic field to make the contacts close or open in order to control the load. A contactor contains more than one pair of contacts, all contacts may be normally open contacts, or all contacts may be normally closed contacts, and some may be normally open contacts and some may be normally closed contacts; like figure 1 Shown: Terminals 1 and 2 are the power supply terminals of the contactor. When voltage is applied to terminals 1 and 2, current will flow through the coil, thereby g...

AI Technical Summary

Problems solved by technology

[0007] 1. The traditional contactor tester uses relays or low-speed switching tubes to control the voltage applied to both ends of the power supply of the contactor. Since the relay or low-speed switching tube itself has a delay error of milliseconds, the pull-in of the contactor The time and release time themselves are also on the millisecond level, even after optimization, it can bring about an error of about 1% to 5%;

[0008] 2. The traditional contactor tester uses a relay or a low-speed optocoupler to measure the change of the contactor contact. Since the relay or low-speed optocoupler itself has a delay error of milliseconds or tens of microseconds, the contactor's The pull-in time and release time are also on the millisecond level, even if they are optimized, they can bring about an error of about 0.2% to 5%;

[0009] 3. The voltage of the test DC power supply cannot be adjusted, so only a DC contactor with a rated voltage can be tested; and the voltage accuracy error is large, and the voltage ripple is large, which will cause the voltage applied to both ends of the contactor's power supply to be different from that of the contactor. The rated voltage difference is relatively large, which affects the accuracy of the test results;

[0010] 4. The processing speed of the processor used is slow, and the time period for the software to run is relatively long, which increases the error of the test results

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