Automatic switching circuit for voltage and current measurement and method thereof

Abstract

The invention discloses an automatic switching circuit and a method thereof. The circuit comprises a voltage sampling loop and a current sampling loop. The voltage sampling loop comprises two voltage sampling resistors, with the voltage sampling resistor I connected with voltage sampling resistor II in series. The voltage sampling loop is connected with the current sampling loop in parallel. The automatic switching circuit also comprises an electric relay with a NC terminal of the relay connected into the voltage sampling circuit and the controlled terminal of the relay connected with a digitoutput channel of an acquisition module of the controlled terminal. A control terminal is connected into the current sampling loop and controls action of the electric relay according to the control signals received from the digit output channels of the acquisition module, so as to connect the current sampling resistor to the circuit or disconnect the current sampling resistor with the circuit, soas to further realizing automatic switching between voltage measurement and current measurement. In the invention, automatic identification of types of acquisition voltage and current signals connected to the testing equipment can be realized, corresponding testing modes are adopted, the whole testing process is free from human interference, so that the invention features convenient application and full use of existing resources.

Description

technical field [0001] The invention relates to a voltage and current measurement circuit and a method thereof, in particular to a circuit and a method capable of automatically switching voltage and current measurement modes. Background technique [0002] The general data acquisition module can only collect voltage signals or current signals fixedly. If the data acquisition circuit is added such as figure 1 The voltage / current measurement mode switching circuit shown can collect both voltage signals and current signals in a system, but the switching between these two test modes needs to be done manually, that is, the tester needs to be turned on. Cover, connect the jumper sleeve at the voltage / current switching circuit to the circuit in the voltage test mode or current test mode, and then cover the tester cover. If the type of the collected signal changes next time, repeat The above process, therefore, the original manual switching mode is more complicated. [0003] The or...

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Problems solved by technology

[0002] The general data acquisition module can only collect voltage signals or current signals fixedly. If the data acquisition circuit is added such as figure 1 The voltage / current measurement mode switching circuit shown can collect both voltage signals and current signals in a system, but the switching between these two test modes needs to be done manually, that is, the tester needs to be turned on. Cover, connect the jumper sleeve at the voltage / current switching circuit to the circuit in the voltage test mode or current test mode, and then cover the tester cover. If the type of the collected signal changes next time, repeat The above process, therefore, the original manual switching mode is more complicated

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