Disclosure of Invention
The invention aims to solve the technical problem of providing a high-precision direct current resistance tester aiming at the defects in the prior art.
The technical scheme adopted for solving the technical problems is as follows: a high-precision direct current resistance tester comprises a tester shell and a tester circuit;
The tester circuit comprises a power supply module, a gear driving plate module, an energy-saving plate module, a control plate module and a display module;
The gear driving plate module, the energy-saving plate module and the display module are respectively connected with the control panel module;
the power module comprises a power panel and a voltage and current stabilizing power supply and is used for providing power for the tester circuit;
the power module, the gear driving plate module and the inductive load to be detected are sequentially connected in series; the energy-dissipating plate module is connected with the inductive load to be detected in parallel.
According to the scheme, the energy-collapsing plate module comprises a voltage filtering acquisition unit and a reverse charge release unit; a reverse charge discharging unit in the energy-dissipating plate module, which comprises 6 diodes D1 to D6; the sum of the parallel connection of D2 and D5 and the sum of the parallel connection of D3 and D6 are respectively connected with D1 and D4 in series after being connected in series to form a release channel, wherein the positive electrode of D4 is connected with the negative electrode of the current, and the negative electrode of D1 is connected with the positive electrode of the current; the voltage filtering acquisition unit in the energy-collapsing plate module is a filtering capacitor.
According to the scheme, the control panel module is provided with the RS232/RS485 communication interface and the USB flash disk data communication interface.
The invention has the beneficial effects that: the device overcomes the defects of poor testing precision, time consumption and labor consumption of the conventional tester on the inductive load.
Detailed Description
The present invention will be described in further detail with reference to the following examples in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
As shown in FIG. 1, the high-precision direct current resistance tester comprises one test instrument and one test wire set. The tester is connected with the test wire through a binding post. The test end of each test line is provided with a test clamp, which is more convenient for directly connecting test samples,
Comprises a tester shell and a tester circuit;
The tester circuit comprises a power supply module, a gear driving plate module, an energy-saving plate module, a control plate module and a display module;
The gear driving plate module, the energy-saving plate module and the display module are respectively connected with the control panel module;
the power module comprises a power panel and a voltage and current stabilizing power supply and is used for providing power for the tester circuit;
the power module, the gear driving plate module and the inductive load to be detected are sequentially connected in series; the energy-dissipating plate module is connected with the inductive load to be detected in parallel;
The gear driving plate module receives signals of the control plate module and determines gears; the current stabilizing source output current of the power supply module is controlled by a step switching control circuit in the gear driving plate module. When different gears are selected, different stable currents are output; for example: 2.5 omega-gear corresponding current value bit 10A; a current value bit 5A corresponding to 5 omega; 25 omega is 1A;250 omega is 100mA;2500 omega of 10mA;25000 omega 1mA; when constant current flows through the inductive load to be measured, the inductive load is charged to convert the inductive resistance value of the load into pure resistance, and a stable voltage signal Vx is generated, and the current flowing through Rx and the direct current resistance of the load can be calculated according to kirchhoff current law and ohm law. After the measurement is finished, the load end stores certain reverse charges, and the charges are released through the energy-bursting plate. The more charge is stored the more the corresponding squealer sounds. The negative silent alarm indicates that the charge release is complete.
As shown in fig. 2, the crash panel module circuit is described as follows:
1. the energy-dissipating plate P5 is connected with the control plate P3.
2. I+ in the energy-collapsing plate is connected with an external test line current anode.
3. I-in the energy bursting plate is connected with an external test line current negative electrode.
4. V+ in the energy-collapsing plate is connected with an external test line voltage anode.
5. V-in the energy-bursting plate is connected with an external test line voltage cathode.
The energy-collapsing plate comprises 6 diodes D1 to D6; the sum of the parallel connection of D2 and D5 and the parallel connection of D3 and D6 are respectively connected in series with D1 and D4 after being connected in series to form a release channel
The power panel provides a required power supply for the high-precision direct-current resistance tester. In this embodiment, the power supply section is designed with 4 sets of outputs in total. Two 5V groups, ±15v groups and one 24V group, respectively.
The control panel module is provided with a DS18B20 temperature acquisition chip which can monitor the ambient temperature in real time and provide temperature coefficient correction for the resistance measurement result.
1. A standard RS232 interface is provided.
2. A standard RS485 interface is provided.
3. A CAN bus is arranged in the controller.
4. Providing temperature compensation.
5. And collecting a voltage signal. (when the voltage is more than 2.5V, the judgment can be automatically performed, and then the voltage division acquisition is performed)
6. Current signals are collected.
7. A standard JTAG port (upgradeable) is provided.
The circuit diagram of the control board module is shown in fig. 3, wherein the 20P ox horn seat in the control board module is connected with the P10 in the driving board module through a 30cm short flat cable. The pins 6, 8, 10, 12, 14 and 16 in the control panel module are used for switching different acquisition resistors, and the pins 18 and 20 are used for carrying out voltage gear selection on the U1. And the output current value is equal to the selected voltage divided by the pickup resistance.
The control panel module P3 is connected with the energy-dissipating plate P5, wherein the 1 pin of P3 corresponds to the energy-dissipating plate V+ and the 2 pin corresponds to the energy-dissipating plate V-.
It will be understood that modifications and variations will be apparent to those skilled in the art from the foregoing description, and it is intended that all such modifications and variations be included within the scope of the following claims.