Multimeter capable of preventing wrong gear selection

Abstract

The invention provides a multimeter capable of preventing wrong gear selection. The multimeter comprises probes (10), a measurement module (11), a dial (12), a multi-gear button (13), a gear determination module (14), a voice module (15), a loud speaker (16), a master control one-chip microcomputer (17), a controlled switch (18) and a confirmation button (19). The gear determination module (14) that is connected with the multi-gear button (13) is used to determine a gear that is selected by the multi-gear button (13). The voice module (15) generates a voice signal that is used for prompting the selected gear according to a determination result of the gear determination module (14); and the voice signal is played by the loud speaker (16). After confirmation, the master control one-chip microcomputer (17) controls opening and closing of the controlled switch (18), so that the probes (10) and the measurement module (11) are connected to realize parameter measurement. According to the invention, beneficial effects are as follows: prompting and user confirmation processes are provided and thus it can be avoided that a user selects a wrong gear, so that overload damage caused by wrong gear selection by the multimeter can be effectively prevented.

Description

technical field [0001] The invention relates to an electronic multimeter, in particular to a multimeter for preventing wrong file selection. Background technique [0002] The multimeter is a multi-functional instrument tool, which has various measurement functions such as measuring voltage value, resistance value, and current value. Usually, the multimeter is connected to the circuit with probes, and the multimeter body has a built-in measurement module, and the outside of the multimeter has a dial for displaying readings and a multi-level knob. The user switches the measurement function of the multimeter by aiming the knob at different positions. For example, when the knob selects the DC voltage gear, the function of the multimeter is equivalent to a DC voltmeter. At this time, the multimeter should be connected in parallel to the component under test; For a DC ammeter, the multimeter should be connected in series with the component under test. It can be seen that when t...

AI Technical Summary

Problems solved by technology

It can be seen that when the selected gears are different, the connection method of the multimeter must also be adjusted accordingly. If the selected gear does not match the connection method, the multimeter may be damaged due to overload.

In addition, multimeters often have gears with different ranges. If the measured signal value obviously does not match the range of the selected gear, it may also cause overload.

[0003] In practical applications, due to the user's unfamiliarity with the operation of the multimeter, or negligence, etc., the wrong file selection often occurs, which is one of the main reasons for the overload damage of the multimeter.

Although the existing multimeter is specially equipped with a buzzer to warn the user to disconnect the test leads immediately when it is overloaded, because the wrong gear selection has occurred and the multimeter has been powered on during the alarm, it is still unable to effectively prevent the accident caused by the wrong gear selection. Multimeter damage caused by

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