0 to ±5A Current Meter 5-Digit DC Current Meter of High Precision (with Non-isolated Interface)

0 to ±5A Current Meter 5-Digit DC Current Meter of High Precision (with Non-isolated Interface)

Attention:
- Please refer to the description and wiring diagram below before purchase and installation. Paper instructions are not provided for the time being. If the wiring is wrong or improperly used, the meter will be damaged directly! Please clarify the wiring sequence before connecting!
- Non-isolated meter adopts a common ground design. The negative pole of the power supply terminal of the meter and the negative pole of the test terminal are completely connected. If the same main power supply is used, its test terminal cannot be connected in series to the positive pole for testing, which will directly short-circuit the meter. The measurement must be in-line with the load or ensure no over-current. The wiring sequence should be: power supply V+->load->test terminal red wire->test terminal black wire->power GND. The measurement black wire can only be connected to GND!
- Isolated meter does not have the above problems, and can be connected to the V+ terminal, or the GND terminal, or any node in the middle of the circuit to be tested. Similar to a multimeter, it can measure the current of any node in the circuit.

Read Before Purchasing:
(1) The interfaces of our module are clear and its performance is stable. Please combine the information provided by us and then perform functional verification corresponding to the experimental conditions.
(2) The basic parameters of this module are mentioned below. Schematic diagram and engineering files are not provided. If you have operational problems, please consult customer service.
(3) Before using the module, please read the information of this module to understand power supply and usage restrictions, so as to avoid damage to the module due to improper operation.
(4) Real module parameters, functions and pictures are provided. All modules have passed inspection before delivery.

Module Parameters:
- Module Type: Current Meter
- Supply voltage: 4~30V
- Measuring range: 0~±5A
- Input Impedance: 10mΩ
- Product power consumption: 15mA (min: 14mA; typical: 15mA; max: 16mA)
- Display resolution: 0.1mA
- Measurement accuracy: 0.04%+0.04% [±(reading%+range%) (Tcal 23℃±5℃)]
- Reverse connection protection: yes (reverse connection voltage<=30V)
- Input over0current protection: None (Maximum input current: ±7AC)
- Communication interface: UART_3.3V (9600Baud; 8Bits; None Parity; 1 Stop Bit)
- Communication protocol: for Modbus (support 0X03, 0X06 command C)
- Module weight: 14.5±1g
- Module size: 29 x 48 x 28mm (tolerance ±1mm)
- Working temperature: -15 to +85℃

Module Description:
- The ammeter adopts a high-precision reference and sampling resistance scheme, featuring accurate measurement results and high resolution.
- It uses a 10mΩ sampling resistor and the input voltage drop is only 50mV when the input current reaches 5A, which has little impact on the measured system.
- With a bipolar design, it can measure bidirectional positive and negative currents up to ±5A. It can also measure the current normally without distinguishing the wiring.
- Designed with anti-reverse connection circuit. The module does not work when the power supply is reversed, but this will not cause damage to the circuit.
- High input overload current. Input current up to 7A will not cause damage to the circuit. When the current returns to within ±5A, the module can measure the current value normally without restarting.
- The module integrates serial communication function, and the current data of the module can be read back by devices such as single-chip microcomputer and computer (requires USB to serial port module). The use of Modbus protocol is convenient for large-scale integration and industrial applications.

Package Included:
- 1 x Module (with Non-isolated Interface)
- 2 x Connecting Cables

Note:
- Battery and other items pictured are not included, for demonstration purposes only. Thank you for your understanding!


The module has been zeroed and calibrated. If you use this product for a long time or the temperature and humidity change greatly, it may drift a little, and you can perform zeroing and calibration operations on the back of the circuit board. When the current input line is unplugged, its display is not 0. At this time, you can short-circuit the two zero adjustment holes in the figure, and then release the module within about 2S to automatically complete the zero adjustment. The measurement error caused by long-term use can be adjusted by the Calibration Knob in the figure.



Precautions:
(1) Do not use a power supply that exceeds the nominal supply voltage range to power the module.
(2) The voltage should not exceed 30V when reversely connected.
(3) The non-isolated meter adopts a common ground design, and its test terminal cannot be connected to the positive pole in series. The current loop wiring sequence should be: power supply V+->load->test terminal red wire->test terminal black wire->power GND. The black wire of the module measurement can only be connected to the loop GND.

Data Communication Description:
The module communication interface is UART-3.3VTTL, the communication protocol adopts Modbus protocol, and supports 0X03 read (single or multiple consecutive) and OX06 write (single) commands.

FAQ:
Q: What is the situation when the display keeps drifting during current measurement?
A: When testing the product after receiving the good, the user needs to ensure the stability of the current to be measured, so that the stability of the product can be accurately measured. Common errors collected so far are:
1.Battery is connected in series with resistance to provide the current to be measured: as the voltage of the battery gradually decreases during use, the current it generates also gradually decreases, and the display naturally gradually decreases (please use a stable power supply to generate current for testing);
2. Use small package resistors and large resistors to limit current to generate current: small package resistors often have low power and poor heat dissipation. When the current is passed, it will gradually become hot, and the resistance value of the resistor will drift with the temperature drift. I=V/R, R drifts, and I naturally drifts. The principle of large resistance current is similar. For example, when 50mA current to be measured is also required, the larger the resistance value, the higher the power and the faster the heat generation (it is recommended to use a high-power small-value resistor to limit the current to generate the current, such as 50W 50Ω or 50W 50Ω gold-sealed resistor).

Q: Can it be powered by battery?
A: Yes. The module has a wide power supply voltage. Battery power can be used as long as the battery voltage is within the nominal power supply range of the module.